Ecopoly PSU insert PEX fittings meet cNSF-14pw and NSF-61 and are manufactured to ASTM Standards F2159, F877 and CSA 137.5 specifications and are ideal for professional installation of hot and cold potable water systems or do-it-yourself plumbing repairs. Ecopoly PSU insert fittings are compatible with copper PEX crimp rings, stainless steel PEX clamps and PEXLock clamps. They work great with any brand or type of SDR-9 PEX or PE-RT tubing. Rings and clamps are sold separately unless specified in the description. Ecopoly PSU insert PEX fittings are constructed of durable Udel Polysulfone (PSU) resin. PSU is a superior plastic resin that is resistant to stress fractures and extreme temperatures. However, it is susceptible to volatile organic compounds (VOCs) such as bug sprays, certain cleaners, pipe dopes, primers, glues and adhesives. Keep all products made of PSU out of contact with VOCs.