BrassCraft 1/2 in. Nom Compression Inlet x 3/8 in. OD Compression Outlet 1/4-Turn Angle Valve controls water flow to household plumbing fixtures faucets, toilets, dishwashers, icemakers, washing machines, etc. The angle valve is most often used where the water pipe enters the room from the wall. With a 90 degree turn of the valve 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.