Extremely versatile unit! From 32 Degrees, this unit screws onto any CO2 or HPA tank valve and depresses the pin valve by screwing down the knob. Can be used with most Bottomlines and Drop Forwards with rails. Can also be used with Remote Systems or Fill Stations. Improved design is more compact and won't leak! Lightweight anodized aluminum unit with female side hole threaded 1/8" NPT (accepts standard CO2 hose fittings).