The MD41 is a compact, self-contained GPS Annunciation and Control unit. It meets all requirements for external (remote) mode selection and status annunciation for the Garmin GNS 430/530 VHF Communication and Navigation Management System. Dual 20,000 hour lamps are used for all annunciations, internally lighted selection switches and automatic photocell dimming. An external annunciation dimming adjustment is provided for balancing low level light conditions.Version (EDMO# MD41-1468A) is a 28V unit with horizontal orientation compatible with Garmin GNS-430/530 and Avidyne IFD-440/540 models.