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. This Fitting Is Not Intended To Be Connected To Polybutylene Pipe On Both Sides Of The Fitting.