We designed these billet aluminum service port caps to complement our Pure Stealth line of A/C hoses and fittings and then coated them with our proprietary ceramic coating. These caps will provide the finishing tough to a perfect Pure Stealth Reduced Barrier A/C plumbing installation. These caps have an internal 5/16-24 male stud that will allow them to fit any of our reduced barrier or standard barrier service port fittings. These will not work with E-Z Clip service port fittings.