I don't know if I've ever seen the key size posted but if it fits in with no play, you should be fine. It's a half moon shape and it should stick up a 1/16 of an inch. Sorry I could not be of more help other than to guess that the key is about a half inch long. Maybe you could see if some of the sellers here sell them and list a parts number. I'd ask sickbikeparts, they answer emails within an hour or so. and are very helpful.