2 1/4"" clock mount Wt. 7.5 oz. Three independent 24-hour 6-digit (hours, minutes, seconds) solid state timing circuits. Bright incandescent display. Polaroid filter_ Clock is set at factory to accurate time (W.W.V.) Flight time starts on takeoff. Elapsed time is controlled by pilot All three functions have a memory. (once evaluated entire fleets have been updated.) Standard is black. Available in grey. Selected by more than 15 aircraft manufacturers.