This are a Experimentel Oxygen Regulator Setup used by German Air Force,WWII Portable Warbird Oxygen Diluter Demand Regulator , A 14 Regulator is Specifically:Made by Alar Produkts INC., Set include Oxygen Flow Indicator , Oxygen Cylinder Pressure Indicator , all mounted on a wooden plate ,set is used but very good condition,Due to its age it is sold for display only