Liquid Oxygen Quantity Indicator, Pressure Gauge, Bendix 2426-558-A2 USAF
This LOX Quantity Indicator, 0-20 liters, is a pressure gauge which accepts oxygen in liquid form at the inlet and oxygen in gas form exits at the outlet. Must have been a high pressure application judging from its construction (number of screws and thickness of lens). Likely from the 1950s or 1960s, and produced for a US Air Force application per its MIL spec.
It is in experienced condition. The dial markings are clear and the glass and case are intact. Measures 2.5 inches diameter and 2.75 inches deep. See photos.