High visibility white LCD display backlit dot matrix Powers using an external input, 5v/0.5a micro USB input, or 4 AAA batteries Tripod mounting port preinstalled to attach standard camcorder tripods Parameter settings support up to 5 selectable slots Velocity and ROF can be recorded with up to 25 memory slots Measures Muzzle Velocity from 30 m/s ~ 400 m/s (90 ft/s ~ 1200 ft/s). Equipped with a spacious 36mm diameter tube to accurately measure desired unitsSpecifications: Brand AceTech Compatibility 4.5mm, 6mm, 8mm, and 18mm BBs Length 130mm X 108mm Height 61mm Color Black 1X Chronograph