The digital timer is a countdown timer and stopwatch in one. Great for math exercises, science experiments, timed tests, games, classroom management, and more! Includes one AG13 button-cell battery. Sticks to whiteboards or any magnetically receptive surface. Measures approximately 2-1/8"" x 3-3/8"" x 1/4"". Sold as a pack of 3 timers.- A countdown timer and stopwatch in one.- Great for a variety of timed classroom activities.- Sticks to whiteboards.- Pack of 3 timers.- Sold as 3 pieces/Bundle..