... 50 x 18 mm 8 in 1 Function: Digital altimeter, with digital barometer, digital compass, weather forecast, time , calendar, thermometer , and backlight. Altimeter : -700 ... 256pcs records Compass: show bearing in degrees and cardinal point Thermometer : In oC / oF format Clock: In 12 hours or 24 Hours format ... by 2 x AAA batteries 2012 HOT SELLING 8 In 1 Digital Compass Altimeter Barometer Thermometer