Easy to use timer has a repeat memory function for repetitive tests. Three button operation can be learned in less than 10 seconds. Count down from 100 minutes to one second. Memory retains last programmed time. Alarm may be silenced manually or turned off automatically after 30 seconds. Magnetic back allows timer to be placed on any metal surface or use Velcro strip provided to mount unit anywhere. Size is 1-13/16" x 3-1/2" x 1/2" and weight is 1.2 ounces. Supplied with battery providing two years of normal usage.