The timer is very easy to use and adjust. It comes with 3 modes: Clock, Stopwatch, and Interval Timer. I've used it most as an interval timer for the LICK IT Tabata routines I've begun to put together for myself. I set the seconds I need (for standard tabata, that's 10 seconds and 20 seconds) and then the rounds (for standard tabata, that's 8 rounds). Then I click the little button on the side and it starts the timer for me and I get ready to work.
The timer beeps between each set of work and rest. For example, for my tabata workouts it beeps after the first 10 seconds and then after the second 20 seconds... around and around until the 8 rounds are completed. At the end of the 8 rounds, it beeps continuously to let you know that the rounds are complete. You have to press the little button on the outside once, let it beep again, and then press it again for the beeping to completely stop.
The timer then resets itself to the last information you put into it, so if/when you're ready to go for another round of 8, then all you have to do is push the little button on the outside again and it will start all over again.
I use the stopwatch for my 1 minute breaks in between rounds.
Super easy-peasy to use. The interval timer is perfect for tabata workout or HIIT workouts. The stopwatch is perfect for things like sprints or time challenges.