Water-resistant stopwatch counts up to 24 hours with resolution of 0.01 second for the first 40 minutes and 1 second resolution thereafter. Has lap function. Also features an alarm clock and a calendar. Electro-luminescent display is easily read in the dark and will provide about 4 hours of continuous illumination. Excellent for HPLC, TLC, electrophoresis, dark rooms and nocturnal behavioural studies. Size is 2.9” x 3.25” x 3/4”.