Check the listing for details. EFIELD 50 PCS 1/2" PEX Pipe A F1960 Plastic Expansion Rings-NSF Certified. Condition: New. Listed at 10.99 USD. For Use with 1/2" PEX-a TubingDirectly from One of the Biggest Pex Systems ManufacturersCompatible with all Types of Brands of Pex A Pipe/Tubing,Compatible with Expansion Fitting System, NOT Compatible with Stainless Steel Clamp & Copper Crimp Ring SystemsCertified to ANSI/NSF-61 and ASSE 1061 Product Standard. Meet the Standard F1960;Need to Order Expander Tool + Pex Sleeves / Ring Separately; Only for Pex A Pipe/Tubing Fitting Expansion Style ConnectionFor Use with 1/2" PEX-a TubingDirectly from One of the Biggest Pex Systems ManufacturersCompatible with all Types of Brands of Pex A Pipe/Tubing,Compatible with Expansion Fitting System, NOT Compatible with Stainless Steel Clamp & Copper Crimp Ring SystemsCertified to ANSI/NSF-61 and ASSE 1061 Product Standard. Meet the Standard F1960;Need to Order Expander Tool + Pex Sleeves / Ring Separately; Only for Pex A Pipe/Tubing Fitting Expansion Style Connection