This Polyphenylsulfone ASTM PPSU F1960 coupling is used to make a straight transition between WaterPEXa tubing. This 1 inch F1960 by 1 inch F1960 coupling must be joined to the WaterPEXa tubing using a F1960 PEX sleeve to form a fast, reliable, and permanent seal. It is recommended that a specialized tool be used to make the connection.