3/4" Barb Coupling Pex X Polybutylene Is Used To Connect Polybutylene Pipe To Pex Pipe. It Is Made From Forged Brass Which Is 15% Stronger Than Brass Counterparts And Are Free Of Imperfections. This Coupling Is Certified By The Canadian Standard For Pex Pipe And Fittings, As It Has Passed Pressure Testing At Three Temperatures. It Has A Maximum Working Pressure Of 690Kpa. Includes 2 Rings And Is Made From Forged Brass.