The Caldwell Ballistic Precision Chronograph Premium Kit with Bluetooth offers everything needed for accurate recording of velocity data. The kit includes the Chronograph, IR LED light kit, carry case, and tripod. Caldwell achieved higher accuracy by pairing a high-speed 48 MHz processor with a circuit featuring am advanced data interface which allows the units to be calibrated right after factory assembly. This gives you +/- .25% accuracy. The chronograph features a simple-to-use interface. It displays velocity in feet per second or meters per second on a large LCD screen. It also delivers shot string velocity data via Bluetooth to a smart phone. A phone application is available for free and records data on the load and environmental conditions. The app auto-calculates average velocity, standard deviation, min, max, and velocity spread from shot strings. Data can be stored or exported through email. Sunshades are extra wide to further assist on sunny days. The Chronograph measures from 5-9,999 fps. The 1/4-20 threaded housing is for tripod mounting. The Caldwell Chronograph operates on 1 9V battery (not included). Chronograph measures between 5-9,999 fps Can display fos or mps Large LCD screen Includes IR Led light kit, Carry case, tripod, and sun shades Connects to phone with Bluetooth technology Further supported by a phone application