Takes guesswork out of analyzing ammunition performance. Extra large shooting area for accurate shot placement and easier setup. Displays 9 strings of fire, 99 shots each, plus delete string or current shot, high and low velocity, extreme spread, standard deviation and average velocity. Threaded for 1 4-20 tpi camera tripod. Measures speeds from 22 to 7000 in fps or meters per second. Optional indoor light kit required for indoor use. Light kit available by special order. Optional Indoor Lighting System available. PC USB Interface provides everything needed to display all your data from the ProChrono Digital chronograph in an easy-to-read format on your computer screen. Control all of the chrono functions from your computer, list velocity strings, compute ft./lbs. of energy, power factors, and even create graphs for easy data comparison and interpretation. Uses the computer USB port for a cable connection to the ProChrono Digital chronograph. User-friendly software allows two chronographs to be used with one PC for easy side-by-side chronograph velocity comparisons. Includes 25 ft. long USB cable, USB adapter interface, and software CD.