Made in USA. Replace the unsightly plastic or mismatched service port caps on your A/C system with our new Pure Choice Polished Aluminum Service Port Caps. Simple screw-on installation. An O-ring inside of the cap seals your service port and protects the schrader valve from debris. These caps will fit all Vintage Air E-Z Clip and ProLine service port fittings with metric internal threads. These caps will Not work on Vintage Air Reduced Barrier or Standard Barrier service ports fittings which have 5/16-24 internal threads.