The SharkBite 1/2-in barb x 3/8-in OD compression straight stop quarter-turn valve controls water flow to household plumbing fixtures. The straight stop valve is used where the water pipe enters the room to allow for easy shut-off of water flow to the end fixture allowing for maintenance and repair without having to turn water off to the entire home. The SharkBite 1/2-in barb end can be connected to PEX pipe using copper crimp rings or stainless steel clamps. The 3/8-in compression outlet with the supplied ferrule and compression nut, can be used with 3/8-in OD pipe or 3/8-in supply line. This valve is best suited for use on toilets, faucets, and dishwashers. Sold as a 4-pack.