LASCO 19-9531 Coupling Barb Fitting with 5/8-Inch x 5/8-Inch Barb, Nylon Nylon barb fitting 5/8-inch x 5/8-inch barb coupling Use on I.D. size poly tubing Working pressure 150 psi, up to 175 degree Fahrenheit Do not use with acid based fertilizers, bromine, chlorine, fluorine, xylene or any acids