6 Best Thermal Imaging Air Rifle scopes

Best Thermal Imaging Air Rifle Scopes offer a significant advantage for hunters, pest controllers, and night shooters by enabling precise target detection in total darkness and adverse weather conditions. Unlike traditional optics, these scopes rely on heat signatures, allowing users to spot animals or intruders through fog, smoke, vegetation, or complete blackouts. With features like high-resolution sensors, fast refresh rates, digital zoom, laser rangefinders, and customizable reticles, thermal imaging scopes transform air rifles into highly accurate tools for day or night use. Their lightweight construction and user-friendly interfaces make them ideal for both beginners and professionals seeking reliable performance, extended range, and modern convenience in challenging environments.

Best Thermal Imaging Air Rifle scopes

1.Pulsar Thermion 2 Pro Thermal Riflescope

Pulsar Thermion 2 Pro Thermal Riflescope

 

 

The Pulsar Thermion 2 Pro sets a new benchmark in thermal imaging riflescopes with unmatched clarity, advanced thermal detection, and feature-rich performance. Whether you’re tracking varmints at night or engaged in professional-level pest control, the Thermion 2 Pro offers elite-tier functionality in a rugged, waterproof design.

At the heart of this scope lies a 640×480 microbolometer sensor with a 17μm or 12μm pixel pitch (depending on model), delivering crystal-clear thermal images, even in zero light conditions. Coupled with F/1.0 germanium optics, the scope achieves detection ranges of up to 2,000+ yards, making it overkill for most air rifle needs — but perfect for demanding precision shooters.

Key Features

With its ultra-sensitive sensor and fast aperture optics, the Thermion 2 Pro can detect heat signatures beyond 2,000 yards, which is especially useful for long-range observation or large property surveillance.

The scope includes Wi-Fi connectivity, letting you pair it with Android or iOS devices. Use the Stream Vision 2 app for real-time streaming, firmware updates, file transfers, and even remote control of scope functions.

PIP mode magnifies your aiming zone in a small window, enhancing precision without sacrificing your awareness of the full field of view — ideal for accurate zeroing and fast target engagement.

Rated to withstand full submersion in up to 1 meter of water for 30 minutes, the scope performs flawlessly in rain, snow, or wet environments — no need to worry about field conditions.

Capture thermal video in .mp4 format and still images in .jpg, all stored on the built-in 16GB memory. Perfect for reviewing hunts, training footage, or sharing moments with friends.

Choose from 8 different color palettes like White Hot, Black Hot, and Red Monochrome to match your preferences and reduce eye fatigue. The scope also includes up to 8x digital zoom for maximum detail.

Specifications (Thermion 2 XP50 Pro & XG50 Models)

Feature Specification
Sensor Resolution 640×480 @ 17μm or 12μm
Display AMOLED 1024×768
Frame Rate 50 Hz
Detection Range Up to 2,500 yards (XG50)
Magnification 2-16x (XP50) or 3-24x (XG50)
Battery Life 10+ hours
Weight ~31.7 oz
Waterproof Rating IPX7
Memory 16GB internal
Recoil Rating Up to .375 H&H, 12-gauge, 9.3×64
Zeroing Profiles Multiple save slots
Reticles Customizable options

Pros

  • Unmatched detection range (up to 2,500 yards)

  • Built-in video and image recording

  • App-controlled remote viewing and operation

  • High-precision PIP mode

  • Custom color palettes for comfort and visibility

  • Dual-battery system with hot-swappable external battery

  • Fully waterproof (IPX7 rating)

  • Recoil rated for high-caliber weapons — extremely rugged

Cons

  • Heavier than most air rifle scopes

2.ATN Thor 5 LRF 640 Thermal Scope

ATN Thor 5 LRF 640 Thermal Scope

 

The ATN ThOR 5 640 2-20x LRF is a powerhouse in thermal optics, blending cutting-edge imaging technology with advanced ballistic features. Built for professionals, this scope comes bundled with a Garmin Xero C1 Pro chronograph, a 64GB V30 MicroSD card, and a protective EVA case — making it an all-in-one solution for hunters, range shooters, and serious air rifle enthusiasts.

At its core, the ThOR 5 640 boasts an ultra-sensitive 640×480 resolution thermal sensor with a 12-micron pixel pitch. This advanced sensor delivers crisp, high-contrast thermal imaging in total darkness or challenging light conditions. When paired with its 5-40x smooth zoom, users can engage targets at both short and extreme distances with surgical precision.

Key Features

With a 12µm sensor and HD 1280×960 display, the ThOR 5 delivers stunningly sharp thermal visuals. The scope excels in low-contrast environments, highlighting minute temperature variations that would otherwise go unnoticed — crucial for detecting camouflaged game or tracking movement through dense brush.

The integrated laser rangefinder provides instant, accurate distance readings up to 1,000 yards. Combined with ATN’s ballistic calculator, it automatically factors in wind, humidity, angle, and more — ensuring that every shot counts, especially at long distances.

The included Garmin Xero C1 Pro chronograph measures projectile speeds from 100 to 5,000 fps, offering critical data for perfecting your air rifle setup. Whether you’re tuning pellets, slugs, arrows, or BBs, this system gives you the precise measurements needed for dialing in trajectories with pinpoint accuracy.

Capture every moment with 1280p @ 60 fps video recording, directly stored to the included 64GB MicroSD card. Ideal for reviewing shots, training, or sharing footage with others.

Rugged and ready, the ThOR 5 operates from -20°F to 120°F, and is weather-resistant, with sealed construction to handle dust, moisture, and recoil. It’s rated to handle powerful calibers, but it’s also perfectly suited for precision air rifles.

Specifications

Feature Details
Sensor 640×480, 12µm
Magnification 2-20x (model specific: 5-40x available)
Laser Rangefinder Built-in, up to 1000 yards
Video Recording 1280×960 @ 60 fps
Battery Life Up to 10 hours
Ballistic Calculator Integrated
Reticle Customization Yes
Zoom Type Smooth digital zoom
Operating Temp -20°F to 120°F
Detection Range 1250m to 3300m
Storage 64GB MicroSD card (included)
ITAR Compliance Yes – U.S. export controlled

Pros

  • Exceptional clarity with 640×480 thermal sensor

  • Built-in LRF and ballistic calculator for precise shots

  • Full HD recording with large storage included

  • Smart features with Wi-Fi, app control, and firmware updates

  • Includes Garmin chronograph for data-driven accuracy

  • Recoil- and weather-resistant for real-world use

  • Long 10-hour battery life

  • Smooth digital zoom with customizable reticles

Cons

  • On the heavier side for small-frame air rifles

3.Pulsar Thermion 2 LRF Thermal Riflescope with Laser Range Finder

Pulsar Thermion 2 LRF Thermal Riflescope with Laser Range Finder

 

 

The Pulsar Thermion 2 LRF XL50 is the pinnacle of Pulsar’s thermal riflescope line. Purpose-built for hunters, professional pest controllers, and tactical shooters, it delivers exceptional imaging, precision ballistics, and unmatched adaptability. With a 1.75x base magnification and up to 8x digital zoom, the XL50 gives air rifle shooters and long-range marksmen a thermal solution that balances a wide field of view with detailed zoomed-in target recognition.

What sets the Thermion 2 XL50 apart is its native 1024×768 thermal sensor, a serious leap above most competitors. Paired with <35 mK NETD sensitivity, the scope detects even the most subtle thermal signatures — ideal for spotting small or camouflaged targets in dense terrain. Add a fast aperture Germanium F50/1.0 lens, and you’re looking at an optic that can identify heat sources clearly from over 2,500 yards away.

Key Features

The XL50’s 1024×768 thermal core (with a 12μm pixel pitch) offers stunning clarity and ultra-fine detail in thermal imagery. The high-resolution AMOLED display enhances this with deep contrast, even in sub-zero conditions.

With an 875-yard laser rangefinder, the XL50 precisely measures distance and feeds real-time data into its built-in ballistic calculator. This tool automatically adjusts your reticle based on factors like range, angle, and environmental conditions — giving you exact shot placement with confidence.

The XL50 offers 8 thermal color palettes, including White Hot, Black Hot, Red Monochrome, and Ultramarine. Picture-in-picture (PIP) mode magnifies your target zone in a small overlay while keeping the full field of view visible.

Powered by dual Li-ion batteries, the scope delivers 10 hours of continuous use. Its instant start-up mode lets you conserve energy and react quickly — a must-have for mobile shooting or ambush scenarios.

Control the XL50 remotely, stream video in real-time, and manage settings using Pulsar’s Stream Vision 2 app. You can even transfer videos and images via Wi-Fi or update firmware without removing the scope from your rifle.

With IPX7 waterproofing, this riflescope operates in rain, snow, and even after submersion in 3 feet of water. It’s recoil-rated up to .375 H&H, 12-gauge, and 9.3×64, offering exceptional durability.

Specifications – Pulsar Thermion 2 LRF XL50

Feature Specification
Thermal Sensor 1024×768 resolution, 12 µm pixel pitch
NETD Sensitivity <35 mK
Display AMOLED 1024×768
Frame Rate 50 Hz
Base Magnification 1.75x
Digital Zoom Up to 8x
Detection Range Up to 2,515 yards
Laser Rangefinder Range 875 yards
Battery Life Up to 10 hours
Recoil Resistance Up to .375 H&H, 12-gauge, 9.3×64
Operating Temp -25°F to +122°F
Weight 36.33 oz
Video/Photo Recording MPEG-4/.jpg on 16GB internal memory
Waterproof Rating IPX7
Connectivity Wi-Fi, Stream Vision 2 app, Bluetooth remote

Pros

  • Ultra-high resolution thermal sensor (1024×768)

  • Integrated laser rangefinder + ballistic calculator

  • Video/still photo capture with built-in 16GB storage

  • 8 color palettes + PIP mode for target magnification

  • Long battery life with hot-swappable power

  • Wi-Fi connectivity with smartphone integration

  • Fully waterproof and recoil-rated for big calibers

  • Bluetooth remote control included for silent operation

Cons

  • Heavier than some lower-end air rifle scopes

4.ATN Thor LT Thermal Rifle Scope w/10+hrs Battery & Ultra-Low Power Consumption

ATN Thor LT Thermal Rifle Scope w/10+hrs Battery & Ultra-Low Power Consumption

 

The Pulsar Thermion 2 Pro is designed for shooters who demand elite-level accuracy, real-time responsiveness, and rugged dependability in any environment. Whether you’re tracking nocturnal pests, managing property security, or hunting in pitch black conditions, this scope delivers superior thermal clarity and user-friendly functionality in a classic 30mm tube design that fits seamlessly onto most rifles—including air rifles.

Weighing just 1.4 pounds, the Thermion 2 Pro offers a sleek, ergonomic form factor with easy top-mount controls, and a comfortable 3-inch eye relief, making it ideal for fast scanning and extended shooting sessions. Beneath the compact exterior is a powerhouse of features: a 60Hz thermal sensor, white hot/black hot imaging, and one-shot zeroing, which together ensure fast acquisition and pinpoint accuracy.

Key Features

The heart of the Thermion 2 Pro is its ultra-sensitive thermal sensor, running at a smooth 60Hz refresh rate. This enables you to detect animal heat signatures even through crops, fog, or complete darkness—crucial for nighttime varmint control or tactical use.

Choose between white hot or black hot display modes to suit your personal preference and environmental conditions. These palettes provide high-contrast images that help you spot movement instantly—even if your target is partially obscured.

The One Shot Zero system simplifies sight-in procedures. After firing a single shot, you can move the reticle to the point of impact and instantly lock in your zero—saving time and ammo, especially helpful for air rifles.

The Thermion 2 Pro is built to mount on standard 30mm rings, making it compatible with a wide variety of platforms. The layout is intuitive and minimal, with top-positioned turrets and controls that are easy to access in darkness or with gloves.

At just 1.4 lb (650g), this scope won’t unbalance your rifle or slow you down during long hunts. It’s a great match for both PCPs (Pre-Charged Pneumatics) and springer air rifles.

Specifications

Feature Details
Sensor 160×120 or 320×240 @ 60Hz
Pixel Pitch 17μm or 12μm
Core ATN Obsidian Core LT
Magnification 3–6x, 4–8x (160); 2–4x, 3–6x, 5–10x (320)
Display 1280×720 HD Micro Display
Color Modes White Hot / Black Hot
Eye Relief 90mm (3.5″)
Mount Type 30mm standard rings
Charging USB Type-C
Battery Life 10+ hours
Weight 1.4 lb / 650g
Reticles Multiple digital patterns
Weather Resistance IP-rated, field-ready
One Shot Zero Yes
Video Recording / Streaming No
Bluetooth / Wi-Fi No

Pros

  • Smooth 60Hz thermal imaging for fast target acquisition

  • One Shot Zero makes sight-in fast and efficient

  • Lightweight (1.4 lbs) and easy to mount on any rifle

  • Ergonomic and balanced for air rifles and compact builds

  • White Hot/Black Hot modes for different target types and conditions

  • 10+ hours of battery life for all-night performance

  • Simple, no-frills operation ideal for new thermal users

Cons

  • Lower resolution compared to premium models (320×240 max)

  • No video recording or streaming features

5.AGM Global Vision Varmint LRF Thermal Riflescope with Laser Rangefinder

AGM Global Vision Varmint LRF Thermal Riflescope with Laser Rangefinder

 

 

The Pulsar Thermion 2 Pro is a high-performance thermal riflescope built for shooters who need uncompromising accuracy, thermal clarity, and rugged reliability in the field. Whether you’re using it on an air rifle for pest control or a centerfire rifle for long-range hunting, this scope delivers elite thermal imaging capability and intuitive controls in a familiar riflescope form factor.

Its 12μm high-sensitivity thermal detector, paired with a fast 50Hz refresh rate, ensures smooth and responsive image rendering in any lighting or weather condition—fog, smoke, brush, or complete darkness. The built-in laser rangefinder is a standout feature in this class, allowing you to quickly determine distances and adjust your shot with pinpoint accuracy.

Key Features

The Pulsar Thermion 2 Pro’s cutting-edge thermal core provides outstanding detection capabilities, letting you identify animals, even those partially obscured by terrain or vegetation, from over a mile away. The 640×512 resolution offers crisp thermal detail essential for air rifle precision.

A built-in LRF (Laser Rangefinder) lets you accurately measure distances to targets up to 2,500 yards. This allows for precise shot placement—especially helpful in long-distance or elevated shooting scenarios, or when compensating for pellet drop in air rifles.

The 1024×768 OLED display provides a vivid and detailed sight picture, and you can switch between several color palettes (e.g., white hot, black hot, red hot) to suit different environments and personal preference.

With 1x, 2x, 4x, and 8x digital zoom, shooters can home in on targets without sacrificing image clarity, giving precise thermal contrast at multiple distances. Combined with optical magnification up to 32x (model dependent), this scope is versatile for everything from short-range pest control to long-range precision.

Capture thermal images or video with the integrated recording feature. With 16GB of internal memory, you can record hunts or training sessions and transfer them later via Wi-Fi for easy sharing or analysis.

Built into a traditional 30mm tube housing, the Thermion 2 Pro mounts easily with standard scope rings. It’s shockproof, waterproof, and designed to operate in temperatures ranging from -25°C to +50°C, making it ready for harsh field conditions.

Specifications

Feature Details
Thermal Detector 12μm, 640 × 512 resolution
Refresh Rate 50Hz
Optical Magnification Up to 4× – 32× (depending on model)
Digital Zoom 1x, 2x, 4x, 8x
Display 1024×768 OLED
Field of View Up to 12.52° × 10.03°
Laser Rangefinder Yes, up to 2500m
Built-in Storage 16GB EMMC
Reticle Options Multiple types/colors
Color Palettes Adjustable (White Hot, Black Hot, Red Hot, etc.)
Wi-Fi Streaming Yes
Video Recording Yes
Weight ~1.44–1.59 lb (depending on model)
Mount Standard 30mm rings
Weather Resistance Waterproof, Shockproof
Battery Life 6–8 hrs typical use

Pros

  • Top-tier thermal resolution (640×512) with smooth 50Hz imaging

  • Built-in laser rangefinder for accurate distance measurement

  • 8x digital zoom + high optical magnification

  • Customizable color palettes and reticles

  • Onboard video recording with generous 16GB storage

  • Wi-Fi for remote streaming and app control

  • Lightweight and air rifle–compatible

  • Rugged build: waterproof, shockproof, weather-ready

Cons

  • Battery life could be longer compared to some rivals

6.Burris Thermal Series Handheld Thermal Vision Device for Night Hunting

Burris Thermal Series Handheld Thermal Vision Device for Night Hunting

 

When it comes to cutting-edge thermal optics for air rifles or precision night hunting, the Pulsar Thermion 2 Pro stands tall among the elite. Designed for serious shooters and hunters, it offers a sophisticated blend of thermal sensitivity, laser precision, and field-ready durability that few scopes in its class can match. With high-end features like a 12μm thermal detector, 50Hz refresh rate, and built-in video recording, it’s one of the most advanced thermal scopes on the market—and a prime choice for air rifle applications.

Key Features

The Thermion 2 Pro utilizes a 12μm high-sensitivity thermal sensor and a fast 50Hz refresh rate to detect heat signatures through total darkness, dense fog, smoke, or heavy brush. Whether you’re pest-controlling on the farm or hunting predators at night, this scope provides exceptional target detection and clarity at long ranges—even beyond 2,000 yards in ideal conditions.

What sets this scope apart is its integrated laser rangefinder, which delivers precise distance measurements at the push of a button. This is a huge advantage when calculating holdovers for air rifle pellets, which are sensitive to drop and drift over distance.

Capture what you see with on-board video recording and image capture, stored on the built-in 16GB EMMC memory. Plus, with Wi-Fi connectivity, you can stream video live or transfer files wirelessly to your smartphone via the Pulsar Stream Vision app.

With a 1024×768 OLED display, visuals are bright, clear, and easy on the eyes—even in total darkness. The scope includes multiple color palettes (White Hot, Black Hot, Red Hot, and more), allowing you to customize your viewing experience for various environments and personal preferences.

The Thermion 2 Pro includes 1x, 2x, 4x, and 8x digital zoom, plus multiple reticle types and color options, making it adaptable to a wide range of shooting scenarios—from close-range ratting to long-range varmint control.

Specifications

Feature Details
Thermal Sensor 12μm, high-sensitivity
Resolution 640 × 512
Refresh Rate 50Hz
Zoom Levels 1x, 2x, 4x, 8x
Display 1024×768 OLED
Laser Rangefinder Yes, integrated
Storage 16GB built-in EMMC
Color Modes White Hot, Black Hot, Red Hot, etc.
Reticles Multiple types and colors
Wi-Fi Yes
Video/Image Recording Yes
Battery Life ~6–8 hours
Weight Approx. 1.4–1.6 lb
Mounting Standard 30mm rings
Durability Waterproof, shockproof, weather-resistant

Pros

  • Outstanding thermal detection range and clarity

  • Built-in laser rangefinder ensures shot precision

  • Customizable color palettes and reticles

  • Wi-Fi and on-board recording for documentation and sharing

  • Lightweight for its class—suitable for air rifles

  • Rugged design for tough environments

  • User-friendly interface and standard mount compatibility

Cons

  • Fixed internal storage—no external SD card slot

Read also;5 Best SWFA SS Air Rifle Scopes

 

Factors to Consider When Choosing the Best Thermal Imaging Air Rifle scopes

1. Thermal Sensor Resolution and Pixel Pitch

The quality of a thermal image begins with the sensor resolution, typically measured in pixels such as 384×288 or 640×512. A higher resolution sensor delivers sharper and more detailed imagery, allowing for better target identification, especially at longer ranges. Pixel pitch, measured in microns (μm), also plays a role in image clarity and sensitivity—smaller values (like 12μm) are generally more sensitive and provide superior performance. For air rifle use, where target size can be small (e.g., rodents or birds), a high-resolution sensor ensures accurate visual confirmation before pulling the trigger.

2. Refresh Rate

The refresh rate, often listed as 50Hz or 60Hz, determines how smoothly moving targets appear on the screen. A higher refresh rate reduces motion blur and lag, which is especially important for tracking fast-moving animals. For air rifle hunters shooting agile or distant game at night, a 50Hz or higher refresh rate ensures that you don’t lose visual contact due to choppy imaging or latency during movement.

3. Zoom Capabilities (Optical and Digital)

Air rifles often engage targets at relatively short to moderate distances, so having versatile zoom options is crucial. Many scopes offer digital zoom levels like 2x, 4x, and 8x. While digital zoom may reduce image quality slightly, it allows for finer aim and better target recognition. Some high-end scopes also offer Picture-in-Picture (PIP) zoom, letting you magnify a portion of the image while keeping your field of view intact. A flexible zoom range helps adapt to varying distances and target sizes without physically moving closer.

4. Reticle Options and Ballistic Tools

Reticle customization—types, patterns, and colors—is more than an aesthetic feature. Air rifles have distinct ballistic curves compared to centerfire rifles, meaning pellet drop needs to be accounted for. Scopes with multiple reticle types, ballistic calculators, or one-shot zeroing features simplify zeroing and improve shot placement. Choosing a scope that allows you to match the reticle to your rifle’s trajectory ensures better precision and adaptability across various shooting conditions.

5. Built-In Recording and Storage

A scope with on-board video recording and image capture capabilities, like those with EMMC storage or external memory support, adds both fun and functionality. You can review shot placement, document hunting trips, or share footage for training or social purposes. This feature becomes especially useful during nighttime hunts when visibility is limited, and documenting each shot is helpful for confirmation and analysis.

6. Mounting and Weight

Weight and mounting compatibility are especially important for air rifles, which are more sensitive to added bulk than larger firearms. Scopes like the Pulsar Thermion 2 Pro, which use standard 30mm ring mounts and weigh under 1.5 lbs, are ideal for maintaining balance and mobility. Always check that your air rifle’s rail system matches the scope’s mounting system and that the combined setup remains manageable for extended field use.

7. Battery Life and Power Efficiency

Thermal scopes consume more power than traditional optics due to continuous image processing and display requirements. Battery life can range from 5 to 18+ hours depending on the model. For night hunting or extended sessions in the field, look for scopes with long-lasting batteries, standby modes, and USB-C charging for added convenience. A dead scope during a critical shot can ruin a hunt, so reliable battery performance is non-negotiable.

8. Durability and Weather Resistance

Field conditions can be unpredictable—dust, fog, rain, and temperature swings are common challenges. A high-quality thermal scope should be waterproof, shockproof, and fog-resistant, and able to function in extreme cold or heat. A rugged construction ensures the scope continues to operate reliably no matter where or when you hunt. This is particularly vital for air rifle users who may be crawling through tight brush or using lighter guns that experience sharper recoil.

Frequently Asked Questions on Best Thermal Imaging Air Rifle Scopes

1. What is the best thermal imaging scope for air rifles under 2 lbs with high resolution?

One of the top choices is the Pulsar Thermion 2 Pro Thermal Riflescope. It features a 640×480 high-sensitivity thermal sensor, 12μm pixel pitch, and a high refresh rate (50Hz), offering crystal-clear imagery even in challenging environments. Weighing just 1.4 lbs, it balances well on most air rifles and uses standard 30mm ring mounts, making it easy to install. Its built-in video recording, adjustable color palettes, and digital zoom (1x–8x) make it both advanced and user-friendly for precision air rifle hunting.

2. How important is refresh rate for thermal scopes used in air rifle hunting?

A high refresh rate (50Hz or 60Hz) is critical when using thermal scopes for air rifle hunting. Air rifles often target small, fast-moving animals such as rabbits or rodents. A higher refresh rate ensures smoother tracking, minimal image lag, and better clarity when panning or aiming at moving targets. Models like the AGM Varmint LRF TS50-640 and Burris BTS 35 both offer 50Hz imaging, making them ideal for dynamic shooting environments where precision timing is key.

3. Do thermal scopes work in total darkness or foggy weather conditions?

Yes, thermal scopes do not rely on visible light. Instead, they detect heat (infrared radiation) emitted by living beings and objects. This makes them exceptionally effective in total darkness, fog, smoke, or even light brush cover. Devices like the AGM Varmint LRF TS50-640 and ATN ThOR 4 640 provide clear thermal images regardless of visibility conditions, making them invaluable tools for night hunters and air rifle enthusiasts operating in unpredictable environments.

Conclusion

In conclusion, thermal imaging air rifle scopes have revolutionized low-light and night-time shooting by offering unmatched visibility, precision, and adaptability in diverse environmental conditions. Whether you’re engaged in nighttime hunting, vermin control, or tactical observation, these scopes provide critical advantages such as high-sensitivity thermal sensors, multiple color palettes, digital zoom, and integrated rangefinding. With robust construction, long battery life, and smart connectivity features, they deliver a dependable and immersive shooting experience. Choosing the right thermal scope ultimately depends on your specific needs, but investing in advanced thermal optics ensures you’re equipped for accuracy and confidence, no matter the challenge