SIENOC Digital Professional Handheld LCD Chronograph Sports Stopwatch Timer Stop Watch Displays Hours , Minutes , Seconds ,Day, Date, Month Material :ABS; Net Wight:45g ; Color: Black Battery Replacement: AG13 Button Battery; It doesn't have a light and it doesn't turn off. Comes with adjustable wrist strap for self timing while running; A must for all sport and technical application. For the directions please download from the link on the shipping babel on the express box