Airspeed Indicator, 900 km/h, Luftwaffe Fahrtmesser Fl.22234 Lily Bomber The pointer is calibrated by

The pointer is calibrated by turning the screw in the lower left corner

The bracket has one spirit level to ensure that the gunsight body is level perpendicular to the line of flight

This valve was used to regulate the vacuum pressure between its source (either an externally-mounted venturi tube

used by bombardiers and technicians to check the proper operation of the Norden Bombsight

or an internal engine-driven compressor) and the system of pneumatically-powered flight instruments

Airspeed Indicator, 900 km/h, Luftwaffe Fahrtmesser Fl.22234 Lily Bomber The pointer is calibrated byHere is a WW2 era German Airspeed Indicator FI. 22234, with a maximum airspeed of ~900 km h. As the airspeed increases, rotating the pointer clockwise from the 6 o'clock position, it rotates 360deg past 0 once 800 km h is exceeded, thus following the airspeed index on the inner scale, up to ~900 km h. According to AircraftCockpits. com, this was used in aircraft such as Do335, Fi103, FW190A7 9, Ta152, Go229, He162, He219, Ju388, Bf109G, Fi103, and