EFS50 ED H-L 5V GRY 066-03137-3300ED 551A Electronic Display Unit | Gray, 5VAC/DC HIRF LightingThe ED 551A Electronic Display unit functions as a Horizontal Situation Indicator (HSI), Attitude Director Indicator (ADI) or Multi Function Display (MFD) used with the EFS-50 system. When the ED 551A is u..