Feature: 1. BATTERY POWERED: The wireless laser timer charges for 5 hours and runs for 8 hours. Adopts battery percentage reminding design. The switch button is on the side of the timer. No need to connect the mobile power supply, easy to use 2. TECHNICAL PARAMETERS: Effective light distance of sprints wireless laser timer is more than 8meter. With five digit display, accurate to 0.001s 3. AUTOMATIC RESET WITH SMALL ERROR: When triggered next time, the timer will automatically reset and enter the next round of timing, without manual reset. The timing error of one hour is less than 0.001s 4. WATERPROOF AND PORTABLE: Racing timer stopwatch adopt toolbox packaging, waterproof and shockproof, compact and portable 5. WIDELY USED: The race clock is used to time the start and finish of the same location, which is an excellent coaching equipment for motorcycle timing, karting lap timing, piling timing, balancing car, roller skating, pet training, track and field training competitions Specification: Item Type: Wireless Laser Timer Material: Aluminum, PC, ABS Power Supply: 18650 lithium ion battery 1500mAh Effective Laser Distance: Approx. 8meter / 26.2ft . Package List: 1 x Timer1 x Reflector2 x Floor Support1 x Support1 x Charging Cable1 x Power Adapter(random color)1 x Storage Box Note: Do not look directly at the laser emitting hole in operation.