This 1/2" stainless steel MPT hex head is a pipe fitting with a hexagonal head and 1/2" National Pipe Taper (NPT) male thread that inserts into female pipe and connects with NPT threads. These MPT fittings are best for for closing and terminating the end of a pipe and are able to create a tighter seal than straight threads. This plug has a hexagonal head for increased leverage during installation and dis-assembly.