This stopwatch is mechanical wind up and has two buttons. - This mechanical stopwatch features 1/5 second, 60 minute register, 60 second sweep. - The top button allows the user to start and stop the stopwatch. - The side button allows the user to return stopwatch hand to zero when stopwatch is in a stopped position. 1. Wind it up before timing 2. Give a firm press to the top button, the timer starts. The top button should make a 'click' when fully pressed. Press again, it stops. 3. You can start/stop it over again to accumulate the time. 4. Press the side button to reset only when it stops
