This lead free CrimpRing (TM) adapter is used to make a straight transition between copper pipe and potable or radiant heating PEX tubing. This 3/4 crimp by 3/4 inch female threaded adapter is made of lead free brass and must be joined to the PEX tubing using a copper crimp ring to form a fast, reliable, and permanent seal. It is recommended that an electric crimp tool be used to make the crimp connection.