1.8'' LED Interval Workout Timer Countdown Stopwatch You can set several groups of training time and rest time.Like 4 Times 1 minutes Training and 30 seconds rest Set as this: F1 01:00 C1 00:30; F2 01:00 C2 00:30; F3 01:00 C3 00:30; F4 01:00 C4 00:30 It also can countdown anytime to zero like countdown 1 hour to 0 or 15minutes to 0 Stopwatch counts up to 99 minutes, 59 seconds and hundredths of seconds 10 seconds to prepare and a beep on 3 2 1 GO!