All of our One-Size-Fits-Most helmets are manufactured by Biltwell. They fit most all head sizes comfortably with the exception of super sized or miniature sized melons. For size specific sized helmets, check out the ultra cool chart presented on Biltwell's site. This should help you figure out your noggin size. Remember to measure at least 3 times to get the best results. Once you have this info, you're just a few clicks away to having your new lid sent straight to you.