CTS quick connect stackable (stem x quick connect) coupling (push type) for PEX, copper, CPVC, and potable plumbing pipe. Stem end of fitting pushes into the quick connect end of other fitting. Eliminates the need to cut small pieces of pipe to join fittings. Can be easily disconnected and reused without any tools. Approved for behind the wall and underground installations without the use of access panels (always check local codes). Holds up to 250 P.S.I. at 75 deg. F. IAPMO, NSF 61, CSA/ASTM and UPC Code Approved.