i use them on my revo. absoltely sick. beefy ass all hell. they come with all of their own drive cups. at least the set for my revo did. im sad to say that i cant use my center set for my g2r but i can still use the drive axles. i've never broken, bent, damaged one. my freind also uses them on all three of his maxx's none damaged either. we've put them through some serious abuse.