I bought this to remove the fan clutch on my Chevy Blazer and it has worked great for that purpose. The wrench holding the pulley in place fitted the pulley on the side with the longer cut hole perfectly, and I was able to use the large wrench to turn the fan clutch with ease. I didn't need the other key for anything, so it was a bit of a waste, but who knows, maybe one day I'll use it for something.