Easy to use: just enter in the desired minutes and press "Start". Count down from 100 minutes, or count up to 60 minutes. Features timeout and automatic rolloever in count up mode. Count-down alarm shuts off automatically after 1-minute. Also has 0.3" LCD, 2-year silver oxide battery, spring clip for clipping to lab coats, magnetic back, and flip-open stand. Dimensions are 2 3/4 x 2 3/4 x 1/2".