Sharkbite, 4 Pack, 1/2" x 3/8" OD Compression, Straight Stop, Quarter Turn Valve Controls Water Flow To Household Plumbing Fixtures, Used Where The Water Pipe Enters The Room To Allow For Easy Shut Off Of Water Flow To The End Fixture Allowing For Maintenance & Repair Without Having To Turn Water Off To The Entire Home, Sharkbite Push Fit End Allows You To Simply Push On To Copper, CPVC Or Pex With No Solder, Clamps, Unions Or Glue, Just Insert The Pipe & The Stainless Steel Teeth Bite Down & Grip Tight, While A Specially Formulated O-Ring Compresses To Create A Perfect Seal, Disassembly Is Just As Fast Using The Simple Disconnect Tool So Fittings & Valves Can Be Easily Changed & Reused, Can Even Be Rotated After Assembly For Easier Installation In Tight Spaces.