Sport Radar Multi-Sport Velocity Detection from Sklz model SR01-000-02 is ideal for tennis, baseball, softball, soccer, football and lacrosse, can be placed behind goals, nets, and rebounders. With the same technology used by the pros, this device measures the velocity of any sporting ball, and can be used solo. It keeps track of your speed during each session, even a record of your all-time best, helping you set personal goals. Has large, easy-to-read, multi-function LED screen, displays in mph (between 15-150) or km/h. Battery operated (4 C batteries not included). New and unused in its original box.