SharkBite 23057LF Stop Valve, 1/2 x 3/8 in Connection, Compression, 80 to 160 psi Pressure, Brass Body

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. Typically used on stub-outs coming out of the wall. Certified for use in potable water systems.