PlumbShop® 1/2 in Nominal Cold Expansion Barb (PEX) x 3/8 in OD Compression 1/4-Turn Angle Stop controls water flow to household plumbing fixtures - faucets, toilets, dishwashers, icemakers, washing machines and more. The angle valve is most often used where the water pipe enters the room from the wall. With an easy-grip ergonomic 1/4-turn handle, you are able to stop the flow of water leading to the plumbing fixture, allowing for maintenance and repair without shutting off the water to the entire home.