The Smart Parts Smart Valve features a high-flow valve design with quarter-turn on/off lever. Low maintenance and easy disassembly for cleaning. The new Smart Valve resembles previous versions, but with one critical difference: it has a built-in safety device. The device extends the threaded neck of the Smart Valve and retains the tank in the event of accidental tank/valve separation. The device also safely vents tank pressure without incidence of significant cylinder "take-off." Tank not included.