Knee Map Holder US Navy T93-H-202500 1948 AR-234 When translated

When translated

This is a WWII-era pneumatic Valve

two remote controls are provided and

B-24 turrets (nose and tail)

According to our friends at DeutscheLuftwaffe:

Knee Map Holder US Navy T93-H-202500 1948 AR-234 When translatedThis is an original Knee Map Holder as used by some pilots of the US Navy post WWII. According to the accompanying bulletin, the board is strapped to the pilots left leg with the map inserted between the plastic panel and the aluminum frame. There is a compass rose mounted to a flexible arm that can be positioned anywhere over the map. A small spring loaded chain can be extended around the center of the compass to the desired course to determine the