This is the Coupling with a Red Vinyl Washer. These Nylon fittings are non-corrosive. May be hand or wrench tightened GHT (Garden Hose Threads) and NPT (National Pipe Threads). 125psi maximum working pressure at 120 deg F and the temp range is -40 deg F to 200 deg F. The size below indicates the Size Hose Shank Fits. The Thread on Male & Swivel is GHT.