This Badin type 10 is a vacuum distributor. The gauge reads suction, This would be vacuum for driving gyro Flight instruments. The 3 knobs allow you to isolate the suction to each instrument. Dirictional Gauge on the left, Artificial Horizon in the middle and the turn & slip on the right.

This instrument was standard equipment for a lot of French aircraft post-ww2 like the Nord 2501 Noratlas, Dassault Flamand, Nord 1100 Ramier. It is also possible that flying instructors could use it to isolate one or more instruments to simulate partial panel flying.