Davtron Model 811B Three in One Chronometer features digital clock, flight time recorder, and an elapsed time meter. It consists of 3 independent 24 hour/6-digit (hours, minutes, seconds) solid state timing circuits. Bright incandescent display. The clock is set at the factory to accurate time (W.W.V.). Flight-time starts on takeoff, & elapsed time is controlled by the pilot. 2-1/4" clock mount. Wt: 7 oz.