ScubaPro A700The A700 second stage, with its metal casing, screw down cover, metal valve housing (barrel) and over molded accents, exhibits a real muscularity in design. Put them together and you get unparalleled breathing performance whether you're cruising the balmy waters of the tropics or venturing beneath a polar ice cap. Rugged full metal second stage case and valve housing (barrel) are able to withstand years of aggressive diving. Metal second stage case