These fittings were designed to fit stock GM Fuel Injection rail applications on LT-1, LS-1 both single and dual fuel lines as well as Ford and Chrysler fuel lines, fuel injection pumps and filters, with same size tubes

 P/N      5800          Pressure / Return
P/N       5810          Pressure       3/8" tube (Green Clip)
P/N       5820          Return        5/16" tube  (Blue Clip)