There is a central eleven position rotary switch, with the levels [in feet] as shown in the photographs, and the connections are to a five [5] pin threaded connector on the rear of the unit.
Vintage Negative Black & White Medium Format Airplane Cockpit Instrument panel
WW2 RAF Air Ministry Aircraft Cockpit Clock 106A/322 1941 Jaeger LeCoultre 8 Day
WW2 RCAF Crashed Aircraft Cockpit Area Yarmouth Airfield Nova Scotia 3.75x2.7In
Aircraft Flight Data Cockpit Voice Recorder Black Box Aviation Orange
Original 1957 Advert Ferranti Artificial Horizon F.H.9 Aircraft Instrument
