Wireless receiving heartbeat signal transmitted from heartbeat brooch; Chest band frequency is AM5.3KHz; Time display: Hour Minute Second; Alarm clock function; Alarm if heart rate exceeds the upper and lower limit valuer(60~220); Timing (maximum time-keeping is 23 hours59 minutes59 seconds99); 12/24 hour displaying format; EL backlight; With key tone; 50m daily water resistant