Believe me, no local parts store can touch this part, I have tried. It's not the quick-connect adaptor, it' s the part that attaches permanently to the fitting on the condenser, that I need. For some reason, whoever converted the car to R134-A years before I bought it, did not have the correct high-side R-134A fitting, so they screwed on a low-side fitting. I see they removed the Schrader valve from the factory fitting, then screwed this fitting on; it contains it's own Schrader valve. The low side of the gauge set will connect to it, not the high side.
What I need to know is: what size is the OEM fitting on the condenser, then I can ask for the correct adaptor/test port.