3/8″ Copper Tube Size x 1/2″ Male Pipe Thread, Quick Connect Adapter, Hold Up To 250 PSI, 1 Piece, No Parts To Assemble Or Lose, Quick Connect Design Allows Quick & Easy Connections Without The Use Of Installation Tools, Great For New Installations Or Plumbing Repair Projects For Pex, Copper, & CPVC Pipe, Just Cut Pipe & Push Pex, Copper Or CPVC Tubing Into Fitting End Until Tubing Seats At Stop, Can Be Disconnected By Pulling Back On Ring & Releasing Pipe, Code Approved For Behind Wall Without Access & Direct In Ground Burial Installations, NSF-14, NSF-61, CSA/ASTM & UPC Code Listed & Approved, Excellent Replacement For Qest & Flare It Type Fittings.