Plotting Board, Streckenzugtafel J., Luftwaffe, WWII 1938 (FLITEC177)
This is a Plotting Board used by Luftwaffe aviators during WWII.
According to collector George Fulford's notes:
Sturdy aluminum 9 cx 10 inches, and I know nothing about it though it seems like a simplified Battenberg computer sized down for in flight use. It has the Luftwaffe stamp on the rear.