Pilot Gifts - This Instrument Wall Clock with Thermometer is fun airplane décor. Our most popular instrument clock, the altimeter, is combined with the airspeed thermometer which are fashioned after the airplane cockpit instruments. Both “instruments” measure about 6 ½" and are made with high impact polystyrene mounted on a light grey backing with glass lenses. The altimeter clock has quartz movement and requires a “AA” battery. The indoor airspeed thermometer shows the temperature measurement in both Fahrenheit and Centigrade.