1. Material: Made of ABS material, light weight and portable to carry outside, handheld device. 2. Graphic LCD screen display: A chronograph with accuracy that gives detailed readings; compact in size, so this chronograph can be taken anywhere. 3. Extra large size diameter: 25mm. 4. Function: Chronograph is a way to measure power since many barrels have twists per inch rifled and the handle needs to spin. Suitable for rate of fire, muzzle velocity, power and prediction distance. 5. 1/4 inch standard adapter interface for tripod mount. 6. The testing must be carried on under a safe environment to prevent yourself and others from being hurt. 7. Overview: Popular among the community, this chronograph is capable of calculating muzzle velocity, power, prediction distance and rate of fire. It features a graphic LCD display, controls and compact size, with accurate readings and ratings. 8. Specifications: Color: Black; Material: ABS; Net Weight: 200g; Size: 13 x 9.5 x 4.5 cm / 5.12 inch x 3.74 inch x 1.77 inch; Testing methods: Handle Test/Tripod Test; Firing Speed: 0-3600 b/m (0-60 b/second); Muzzle Velocity: 15-800 m/s (50-2600 feet/second); 1M High Firing Horizontal Range: 0-400 meters (0-1250 feet); Firing Kinetic Energy: 0-500J; Testing Error ≤ 1.3%; Voltage: DC 4.5V (3xAAA Batteries, not included); Temperatures of Working Conditions: -10 Celsius to +50 Celsius; 1/4 inch standard adapter interface for tripod mount. 9. Package Contents: 1 * Speed Tester. Only the above package content, other products are not included. 10. Note: Light and different displays may cause the color of the item in the picture to differ slightly from the real thing. The measurement allowed error is +/- 1-3cm.