On your mark...get set...go! Great for races, games and other timed activities, this stopwatch is easy to use, making it perfect for both children and adults. Features only 3 buttons - green for go, red for stop, and yellow for clear. Supports science investigations, timed math exercises, elapsed time tracking and a variety of classroom management needs. Shows minutes, seconds and 1/100 seconds on an easy - to - read display. Measures 3"H. Requires one 1.5V button-cell battery, included.