This stopwatch is mechanical wind up and has two buttons. The top button is the winding crown and 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. This stopwatch has a 60 min. register with 1/5 second divisions. Rugged 16 jewel lever movement. Antimagnetic and shock resistant with nickel chrome plated case. This stop watch is great for industrial timing as the dial allows the user to record in 1/5 second intervals or 1/100 minute intervals.