These are products that provide the relevant gas with flow adjustment from the gas sockets installed in the units. Manometered ValvesStandard*SelectGas Type*SelectPRODUCT INFORMATION Body Material: Brass (MS58) Chrome plated Jack: Brass (MS58) Chrome Plated Valve: Plastic or Chrome plated brass, Manometer: 0-16 bar dry type brass 1/8G connection Hose outlet: Brass 9/16