Dim. 21.000 in. Lg; 8.000 in. W; 3.000 in. H; elec 12.0 vac or 12.0 vocw/ 300.0 ma; has capability for 9 vdc battery and 120.0 vac w/ plug in transformer; led display to 6 digits, 12 or24 hr display format; display readout dim. Hr and min 3.5 in. H; seconds 2.5in. H; accurate porm 1 sec per week over temp variation porm 10 degrees f; time base internal quartz crystal oscillator