Made of bakelite, aluminum and steel, this item is in EXCELLENT condition.
This is an excellent specimen of the Contact Altimeter (Kontakt-Hohenmesser) Fl.22317 as used in the WWII-era JU-87 Stuka and JU-88 dive bombers and some ME 110 fighters of the German Luftwaffe. See the illustration of the JU-87 blind flying panel showing the location of this altimeter.
The altimeter has two hands and two front nested knobs. The white pointer indicates the aircraft altitude and the outer knob adjusts for barometric pressure. The second pointer, painted red, is adjusted with the small center adjusting knob with "K" to set a target altitude. At this altitude, an electrical contact (hence the name contact altimeter) is made which releases the bomb or other ordnance. This would relieve the pilot of having to manually release the bomb and allow him to focus on the target and the dive maneuver itself.