We are very proud of this unique desktop combination clock / barometer. Housed in one traditional forged brass case this combination clock / barometer swivels 360½ horizontally and vertically in a brass, perfectly balanced and integrated gimbal so that on one side is the clock and on the other side is the barometer. The gimbal also allows for comfortable viewing from any angle. The clock operates on one 1.5 v battery (included). The aneroid barometer is calibrated for altitudes to 3500' above sea level. This is indeed a very classy and compact instrument. Because of the unique arrangement of a clock on one side of the housing and a barometer on the other, this instrument makes an excellent presentation no matter which side of the desk you happen to be sitting on. Dial: 2-3/8". Base: 5-1/2" (h) x 3" (d). Weight: 2 lbs. 6 oz.