SPC is the original maker of the camber arms so all the other ones you see are either copies or re-labels. The only difference is the quality of the bushings used in the arms, you can see the difference in the pictures. I bought some cheap ones off ebay and a two years later one of the bushings was shot. I ended up reusing the stock arms with Whiteline camber bushing to get it within spec. With the camber being that far out though I would check for damaged suspension parts, I couldn't even get mine to -3 with the Whiteline bushings!