SharkBite crimp rings are used to install barbed fittings with PEX pipe. The crimp fitting is barbed for installing inside the PEX pipe and a crimp ring is used on the outside of the pipe to make a secure connection.
3/4 PVC Trap
1/4 Nylon MPT Plug
1/2 Galv Cap
2-1/8 Forstner Bit