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

The Athlon Optics Cronus ATS Pro 35C-640 is a clip-on thermal that mounts in front of your existing daytime scope — adding 640x512 thermal imaging, ballistic holdovers, and video recording without removing your optic or changing your zero. At 17.2 ounces and 5.2 inches long with ≥9 hours of battery life from dual 18650 cells, it pairs the highest-resolution sensor in the Cronus clip-on lineup with extended runtime for full-night hunting sessions.

Key Features

• 640 x 512 Thermal Sensor with ≤25mK NETD – The 12μm pixel pitch sensor delivers the same ≤25mK sensitivity found across the Cronus ATS Pro lineup — twice the sensitivity of the ≤50mK sensors in most competitors. The 640x512 resolution provides the highest level of thermal detail in the clip-on lineup, with cleaner target definition at longer distances and in low-contrast conditions.

• 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 — the widest FOV in the Cronus clip-on lineup.

• 1280 x 960 OLED Display – 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.

• Stadiametric Ranging – Estimate target distance using the built-in stadiametric reticle overlay. Set a known target height, bracket the target between the ranging marks, and the unit calculates the distance — no laser emission, fully passive operation.

• Ballistic Calculator with Preset Distance Holdovers – Create ballistic profiles in the Athlon Ballistics App, upload them via WiFi, and the unit provides MOA or MIL holdover data for preset distances. Read the corresponding holdover 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.

• 9+ Hour Battery with Dual 18650 Cells + USB-C Backup – Two rechargeable 18650 batteries provide ≥9 hours of runtime — nearly double the runtime of the LRF-equipped 35CL-640. USB-C power supply keeps the unit running when the batteries are 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 the highest-resolution clip-on sensor without the cost of the integrated laser rangefinder. The 35C-640 delivers 640x512 thermal imaging with ≤25mK sensitivity and a 12.5° x 9.4° field of view at a lower investment than the LRF-equipped 35CL-640.

• Predator and varmint hunters working extended night sessions where the 640x512 sensor’s superior target definition matters at distance. The ≥9-hour dual-battery runtime covers a full night of hunting without swapping cells or connecting external power.

• 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.

• Shooters who already own a standalone rangefinder and want to add the best available clip-on thermal sensor to their daytime scope without paying for a second rangefinder built into the unit. Pair this with any handheld rangefinder for a complete thermal solution at a lower total cost.