IST SCUBA Air Tank / Cylinder Valve Knob, Black or Green

Generic air tank valve knob in black color Directional “OPEN” and “CLOSE” arrows molded into knob end Constructed of sturdy hardened rubber with metal plate insert 75 inches in length 5 inches outside diameter The IST SCUBA Air Tank / Cylinder Valve Knob, Black or Green is a durable valve knob for air cylinders, available in black to signify an oxygen air mix or green for Nitrox cylinders.   Constructed of sturdy hardened rubber with metal plate insert, the knob features an outer surface that’s ribbed for easy grip. Measuring 1.75 inches in length, the knob has an exterior diameter of 1.5 inches.   The words “OPEN” and “CLOSE” with accompanying directional arrows are molded into the end of the knob, to help prevent over-tightening.