Compass, Hand Bearing, Type O.6.A., Ref 6A/1248, with Original Case JU-52 When reaching the 12 o'clock

When reaching the 12 o'clock position the aircraft is now at 20

That's about all I can determine without having a manual

which is engaged by turning a small knob on the side

Measures ~3

describes the installation

Compass, Hand Bearing, Type O.6.A., Ref 6A/1248, with Original Case JU-52 When reaching the 12 o'clockHere is a WWII era Hand Bearing Compass, Type O. 6. A., in its original wooden case, as used in aircraft of the British RAF Coastal Command. The 06. A. is hand held compass, used by an observer (hence the "O" designation. Reference numbers for pilot compasses began with "P") to take navigational bearings in situations where a fixed compass could not be used, or to determine correction factors for fixed compasses. The handle holds batteries (not