The Athlon Optics Cronus ATS Pro 35C-400 is a clip-on thermal that mounts in front of your existing daytime scope — adding thermal imaging, ballistic holdovers, and video recording without removing your optic or changing your zero. At 16.7 ounces and 5.2 inches long with ≥10 hours of battery life from dual 18650 cells, it delivers the longest runtime in the Cronus clip-on lineup — built for extended night sessions where swapping batteries isn't practical.

Key Features

• 400 x 300 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 400x300 resolution provides clear target identification at typical predator and varmint engagement distances.

• 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 7.8° x 5.9° FOV – The fast F1.0 germanium lens maximizes infrared throughput to the sensor. The 7.8° x 5.9° field of view provides focused scanning coverage for target acquisition.

• 1200 x 900 OLED Display – The 0.39” OLED produces a sharp, high-contrast thermal image at 1200 x 900 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 + 32GB Storage – Recoil-activated recording captures 3 seconds before and ~7 seconds after every shot automatically. 32GB built-in storage holds hours of footage. Manual recording and snapshots also available, with audio capture via the built-in microphone.

• 10+ Hour Battery with Dual 18650 Cells + USB-C Backup – Two rechargeable 18650 batteries provide ≥10 hours of runtime — the longest battery life in the Cronus clip-on lineup and nearly double the runtime of the LRF-equipped models. 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 thermal clip-on capability at the lowest entry point in the Cronus lineup. The 35C-400 delivers the same ≤25mK sensor sensitivity and ballistic calculator as the LRF-equipped models without the integrated rangefinder — at a significantly lower investment.

• Predator and varmint hunters working extended night sessions where battery life matters more than integrated rangefinding. The ≥10-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 thermal imaging to their daytime scope without paying for a second rangefinder built into the clip-on. Pair this with any handheld rangefinder for a complete thermal solution at a lower total cost.