BrassCraft® 3/8 in FNPT Inlet x 3/8 in OD Comp Outlet 1/4-Turn Angle Ball Stop with Loose Key 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 a few turns of the valve handle, you are able to stop the flow of water leading to the plumbing fixture, allowing for maintenance and repair without turning off water to the entire home.