SharkBite PEX Barb threaded female adapter is made of a lead-free DZR brass, and is an easy-to-install, low-cost solution to connect to PEX tubing. These fittings allow you to connect with either a stainless steel clamp system, or a coppercrimp ring system (each sold separately) and is FNPT threaded on the other side. The SharkBite PEX Barb fittings are compatible for potable water distribution and hydronic heating applications. Approvals: ASTM F1807, NSF/ANSI 61, NSF 372.