Feature: 1. Battery Powered Convenience: Charging for 5 hours, use for 8 hours. Battery percentage reminder design, with switch button on the timer's side. No need for power banks, making the timer user friendly. 2. High Accuracy: Effective light distance: >8m. Five digit display, accurate to 0.001 seconds. Automatically resets and moves to the subsequent timing cycle on subsequent triggering, with a timing error of less than 0.001 seconds per hour. 3. Portable Design: Packaged in a convenient toolbox, this timer is water proof, shockproof, and compact for easy transport and use in various settings. 4. User Friendly Interface: Intuitive controls and clear digital display make the timer easy for users to use and read the timer, enhancing convenience and efficiency. 5. Versatile Applications: This timer is ideal for timing same location start and finish points. Ideal for motorcycle lap timing, karting single lap timing, stakeout timing, balance bikes, rollerblading, pet training, and athletic training competitions. Specification: Item Type: Wireless Timer Material: Aluminum, PC, ABS Power Supply for Timer: 1 x Lithium Ion Battery 1500mAh (Built in) Power Supply for Turnback Device: 1 x Lithium Ion Battery 1500mAh (Built in) Machine Charging Input Voltage: DC 5V Effective Light Distance: > 8m / 26.25ft . Package List: 1 x Timer 1 x Repeater 2 x Reflector 4 x Floor Stand 3 x Stand 2 x Charging Cable 2 x Antenna 1 x Storage Box Note: 1. Do not look directly at the emission hole during use. 2. The product does not come with a power adapter, any DC 5V power adapter can be used to charging the product.