I would definitely agree with YoYExpert, I do own the Axiom and synergy caps that fit it… I do have to say it is quite a different yoyo, and I do have to admit it is alot of fun to use with the caps on, while still keeping the smooth play of the stock Axiom. Although it did take some time for me to get them to sit properly and now my Axiom is very loud, but that is good in my opinion because I like my yoyos to draw as much attention as possible.