Features:Wireless Heartbeat signal transmitted from chest band frequency at AM5.3KHz.Time display with Hour, Minute, Second.Alarm clock function.Alarm sounded when heart rate exceeds the upper and lower limit values(60-220).Timing (max. time-keeping is 23 hour, 59 minutes, 59 seconds, 99).12 or 24 hour display format.Backlight and Noctilucent function.Keystroke tone.Waterproof up to 3 meters.s:Chest transmitter strap: 66-95cm(Elastic)Language: EnglishMovement type: ElectronicWaterproof Depth: 3 metersClose Hooks: BuckleCase Shape: RoundFunction: Alarm Clock, Heart Rate Tracker,24 hour instruction, World Time, etc.Specifications:Material: rubber strap, steel caseColor: blackTotal size:245*22mmDial size:41*16mmPacking Included:1 x Watch1 x English manual1 x Chest transmitter strap Notes:1.The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.2.Please allow slight deviation for the measurement data.