Large LED display for day or night use including back light option, runs of a rechargeable internal battery (NiMH), diameter large enough to test paintballs. You can set BB diameter, weight and convert output into feet per second, meters per second or even auto-calculate for kinetic energy (joules) This chrono can also measure the rate of fire. Tough and ergonomic design, they even styled it to look like field equipment, this model is available in Green. USB cable and instruction manual. Dimensions: W106x D85 x H36 mm Measure the muzzle velocity / bullet speed of your Airsoft Gun  This Chrony can measure muzzle velocity in 3 Unit: m/sec, Joules & round/sec, all in one display  LED Display use for Indoor / Outer, Day Time / Night Time  Built-in rechargeable  battery  Come With USB power cord Full Metal Flash hider tube allow more accurate testing  Tripod Screw to fit camera tripod