Heavy-duty stainless steel Universal Fill Adapter for CO2 and HPA fill stations. Features a large knurled depressing knob and steel depressing plunger. Screws onto any CO2 tank and depresses the pin valve by screwing down the knob. Durable steel construction with female side hole threaded for 1/8in NPT (accepts standard CO2 hose fittings) and a tiny bleed hole for easier tank removal.