Accurately measure your Airsoft Weapons rate of fire and FPS (foot per second) with this vital tool, the Acetech AC6000 MK3 Airsoft Chronograph. Commonly used by weapon modifiers to check if they are within their Airsoft skirmish sites FPS limit. Bluetooth connectivity via Acesoft app, available on iPhone and Android devices Aluminium BB tube Requires 4x AA Battery Premium zip-up carry case Measures Muzzle Velocity from 30 m/s ~ 400 m/s (90 ft/s ~ 1200 ft/s). ROF range: 100~5000RPM Ammo parameter setting: 5 memory slots. Patent Led Lens Design for focusing and diffusing. IR sensor calculates function, Accuracy greatly improved. User-friendly interface with LCD colour screen. 25 shot memory slots for velocity and ROF (Rate Of Fire) Auto-calculate MAX, MIN, AVG by shot memory Energy Per Unit Area Calculation Extra-large tube (diameter 36mm) Tripod Ready mounting hole (Screw for standard camera/camcorder tripods ) More durable: IR sensor self-calibration as well as IR sensor calibration in production Easier to control: Equipped with a 4-way push button Friendly UI: The user is able to directly select and change ammo parameters in the main screen Safer to use: FCC, CE, RoHS compliant