PEX only push-fitting used to permanently transition between PEX pipe and an FNPT thread. Push-to-connect PEX fitting for faster installation compared to traditional PEX rough-in plumbing methods. Requires no special tools, crimp or clamp or PEX rings, increasing productivity. Securely and permanently transition between PEX pipe and an FNPT thread. Green visual indicator lets you know when PEX tubing is inserted to the proper depth and reduces the risk of installation errors.