Athlon Optics Cronus ATS Pro 35CL-640 Clip-On Thermal

The Athlon Optics Cronus ATS Pro 35CL-640 is a clip-on thermal with a built-in laser rangefinder that mounts in front of your existing daytime scope — converting it into a thermal platform with ranging, ballistic holdovers, and video recording without removing your optic or changing your zero. At 17 ounces and 5.2 inches long, it adds thermal and LRF capability to any rifle using the included Picatinny QD mount or optional scope adapter rings (40mm, 50mm, 56mm sold separately).

Key Features

• 640 x 512 Thermal Sensor with ≤25mK NETD – The 12μm pixel pitch sensor delivers the same ≤25mK sensitivity found in the full-size ATS Pro rifle scopes — twice the sensitivity of the ≤50mK sensors in most competitors. You get clean target-to-background separation in conditions where lesser sensors lose targets: fog, light rain, and low-contrast thermal environments.

• Built-In Laser Rangefinder (10–1,600 Yards) – The integrated laser provides ±1 yard accuracy from 10 to 1,600 yards in single-ranging or continuous-ranging modes. Range data feeds directly into the ballistic calculator for real-time holdover solutions — no switching between devices.

• Clip-On Design with QD Picatinny Mount – Mounts in front of your existing scope using the included quick-detach Picatinny adapter. Optional scope adapter rings (40mm, 50mm, 56mm sold separately) clip directly to your objective bell. Either way, your daytime zero stays intact — the clip-on adds thermal imaging without touching your scope.

• 35mm F1.0 Lens with 12.5° x 9.4° FOV – The fast F1.0 germanium lens maximizes infrared throughput to the sensor. The 12.5° x 9.4° field of view provides wide scanning coverage for target acquisition.

• 1280 x 960 OLED Display at 1x Digital Magnification – The 0.39” OLED produces a sharp, high-contrast thermal image at 1280 x 960 resolution. At 1x digital magnification, the thermal image maps directly to your scope’s field of view — your scope’s magnification becomes the system magnification.

• Ballistic Calculator with Real-Time Holdovers – Create ballistic profiles in the Athlon Ballistics App, upload them via WiFi, and the unit calculates MOA or MIL holdovers based on live laser range data. The holdover displays directly on-screen — no dialing turrets, no mental math.

• One-Shot Zero with 5 Profiles – Zero the thermal overlay to your scope at distances from 50 to 500 yards. Five independent profiles (A–E) store different zeroing configurations for different rifles, loads, or engagement distances. A built-in leveling tool helps align the clip-on to your scope during installation.

• 7 Color Palettes – White Hot, Black Hot, Red Hot, Green Hot, Iron Red, Blue Hot, and Sepia.

• Auto-Shot Recording + 64GB Storage – Recoil-activated recording captures 3 seconds before and ~7 seconds after every shot automatically. 64GB built-in storage holds extensive footage. Manual recording and snapshots also available, with audio capture via the built-in microphone.

• 5+ Hour Battery + USB-C Backup – One rechargeable 18650 battery provides ≥5 hours of runtime. USB-C power supply keeps the unit running when the battery is depleted. Eco Mode reduces OLED brightness to 20% for extended sessions. Two batteries and a charging stand are included.

• IP68 Weatherproof, -4°F to 122°F – Fully sealed and submersible (IP68), fog-proof, shockproof. Handles high-caliber recoil and harsh field conditions.

Who It’s For

• Hunters who want thermal capability without replacing their daytime scope. The 35CL-640 clips on in front of your existing optic — you keep your zero, your reticle, and your glass, and add 640x512 thermal imaging and laser rangefinding to the system.

• Predator and varmint hunters running multiple rifles who want one thermal device that moves between platforms. The QD Picatinny mount removes and reattaches in seconds, and five zeroing profiles store configurations for different setups.

• Hunters who need integrated rangefinding with their thermal. The built-in LRF eliminates carrying a separate rangefinder at night. Range data feeds directly into the ballistic calculator for a complete ranging-to-holdover solution.

• Shooters who want to protect their investment in quality daytime glass while adding a thermal layer for low-light and nighttime hunting. A premium daytime scope paired with this clip-on often outperforms a standalone thermal scope at a similar total cost.