Tefen Nylon 6/6 Pipe Fitting, Hex Plug, Gray, 1/2" NPT Male (Pack of 10) Hex plug for closing the end of a pipe or fitting Male National Pipe Taper (NPT) threads for connecting to a female threaded pipe Nylon 6-6 for high strength and flexibility, abrasion resistance, and a higher melting temperature than Nylon 6 Working pressure of up to 200 psi Meets NSF/ANSI standard 61 for drinking (potable) water