HydroPEX couplings are also another one of the most commonly used fittings in the Pex Plumbing industry:
3/8″ PEX x 3/8″ PEX Brass Coupling 
1/2″ PEX x 1/2″ PEX Brass Coupling
3/4″ PEX x 3/4″ PEX Brass Coupling
1″ PEX x 1″ PEX Brass Coupling
1/2″ PEX x 3/4″ PEX Brass Coupling
3/4″ PEX x 1″ PEX Brass Coupling
Rest assured that if you run out of pex pipe and need to make that “connection” the Hydropex brass coupling will be there in the time of need and also provide years of long lasting high quality performance.
