Orbit Drip Irrigation Hose Bib Anti-Siphon Valve, Universal. This valve prevents the backflow of contaminants from the garden hose entering the home water supply. It fits standard outdoor hose faucets and has a 3/4" female inlet x male hose thread outlet. Made of poly material with a pressure rating of 120 PSI, this valve ensures durability and reliability. It comes in a pack of 1 and has a 1/2 inch x 1/2 inch fitting size. To be used outdoors with cold water only.