I don't know the manufacturer of my hard drives. They were on my '65 Mustang when I bought it. These are 14" rims with 4 studs and the center cover hole is 3.25". Since there were no center caps, I decided to try this product to protect the wheel bearing caps and give a more uniform look between front and back. The photos in this review are of my spare tire that was tested. central cover. I had to tap the cap on the rim with a hammer to seat it, but it fits. I think it might be a little high for my liking but I'll probably have to see it on the car to decide for sure as the nuts are sticking out too.