BrassCraft 1/2 in. Nom Comp Inlet x 3/8 in. OD Comp Outlet 1/4-Turn Angle Ball Stop 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 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.