Okay, I am not an engineer, but figuring out what size bolt fits into what size whole is something I'm kind of known for. The instructions say to remove the original bolt from the bar end weight, done. Then insert the counter sunk spacer into the hand gaurd, done. Then use the supplied replacement bolts to re-attach the bar end weight/gaurd combo, d..., um. Huh? The replacement bolt is as wide as the original. It does not fit through the spacer. Period. If I ditch the counter sunk spacer, it works, but looks busch league. Answer: A. The shop gave me the wrong gaurds. B. Go without the spacer. C. I am stupid.