Trident Universal SCUBA Air Tank / Cylinder Valve Knob, Black

All-purpose air tank valve knob Directional “OPEN” arrow molded into knob end Constructed of sturdy, impact-resistant plastic with metal plate insert 1.5 inches in length 1.5 inches outside diameter The Trident Universal SCUBA Air Tank / Cylinder Valve Knob, Black provides a durable, all-purpose valve knob for air tanks.   Constructed of sturdy, impact-resistant plastic with metal plate insert, the knob features an outer surface that’s ribbed for easy grip. Measuring 1.5 inches in length, the knob has an exterior diameter of 1.5 inches as well.   The word “OPEN” and a directional arrow are molded into the end of the knob, to help prevent over-tightening.   Black.