SharkBite® Polybutylene Conversion Coupling is the easiest way to transition your Polybutylene water line to a different type of pipe. This fitting has color-coordinated collars on each end to help you easily identify which side goes with which pipe. The gray-colored collar is intended for use on Polybutylene pipe while the tan-colored collar is intended for Copper, PEX, CPVC or PE-RT. There is no soldering, clamps, unions or glue required when using SharkBite® push-fit fittings.