Functional Explanation 50M/5ATM grade waterproof, you can wear it to swim or bathe, but please don't press any button in water. Use high quality movement, provide precise time and keep, the service life of the at least 2 years. EL backlight clearly display time in the dark, automatically shut down after 5 seconds. Soft rubber band provide comfortable wear. Countdown, Countdown from the time of booking, An alarm sounds after the end. Alarm, provide timed alarms. Week and date, follow the time to automatically update. 1 / 100 standard stopwatch. 12H/24H, 12 hours standard time and 24 hours complete time. Product Material Case Material: Plastic Band Material: Rubber Crystal Material: Resin Buckle Material: Stainless Steel Battery: CR2 Size Information Total Length: 255mm(10.04in) Dial Diameter: 47mm(1.85in) in Dial Thickness: 24mm(0.94in) Perimeter: 230mm~180mm(9.05in~7.09in) Weight: 80g Product Feature 12H/24H Countdown EL Backlight Stopwatch Calendar Week 50M Waterproof Dual Time Alarm Package Contains Watches * 1 Watches English Instruction * 1 TIP Please don't press any button underwater.