The unique feature of this timer is that it also has a true stopwatch mode with 1/100 second resolution, lap and split with a range of 100 hours. In the timer mode it counts down from 100 hours in 1 second intervals. The display indicates time elapsed after the alarm and a memory recalls last timer setting for reuse. Has built-in stand, pocket clip, and magnet. Button cell battery included. Dimensions: 2-5/8"x 2-3/4" x 3/8". Traceable® Certificate is provided. It indicates traceability to standards provided by NIST (National Institute of Standards and Technology)