I bought AFX 39. At first I didn't like the buckle system. As others have said in other posts, the straps are mounted a little too far back. At first the buckle system feels like it is stangling you. Now it doesn't bother me at all and I have begun to really appreciate the quick on and off of the buckle system. The helmet fits perfect. I now prefer it over my Arai street helmet. I measured my head and their sizing info turned out to be right on. I would definately recommend this helmet! (damn I sound like I work for them!)