Original, EXCELLENT WWII German Luftwaffe Oxygen Flow Gauge Fl. 30489. This O2 – Wächte gauge used in the Me109, Fw190, Me262, Do355, Ta152, Go229, Ju87, He72 He219, Ju88 and Me163. Located on the main instrument panel and was part of the oxygen system. Indicated the amount of flow of oxygen to the pilot’s mask. It would flash white whenever a breath was taken to indicate the flow was functioning correctly.