Use to install shut-off in supply line. Made of PPSU (polysulfone). Works on all Brands of PEX pipe. Install with pliers remove with screwdriver. No special crimp tool needed. cNSF-14, cNSF-61, CSA compliant. Fittings and rings included in each bag. Temperature approvals 180 deg F at 100 psi approved for behind the wall and underground applications. Patent pending.