These durable meters have a chrome-plated brass base, a precision flow-adjusting valve and a Polycarbonate Resin high impact hood. The MFR615 is a favorite for hauling tanks equipped for pure oxygen. Connections are 1/8” NPT female pipe thread on the side inlet and a 9/16” 18 male DISS bottom outlet. Meters include 1/4” barbed brass inlet and outlet adapter fittings. Calibrated at 50 psi.