GraLab Model 171  60 Minute General Purpose Timer, 7-1/2" Length x 7-1/2" Width x 2-1/2" Height, +/-0.015% Accuracy 60-minute timer has 6.5 face (Diameter), with two numbered rings; one for tracking elapsed time, and one for stop watch use Two hands for setting by minutes and seconds Electric motor provides + or - .015% accuracy Two outlets for automatic switching between external devices Nonconductive plastic case with rubber base pads help protect against impact, chemicals, moisture, and electrical shock