adidas Kids' X CrazyFast .3 Firm Ground Soccer Cleats size 11K Designed with synthetic/coated textile uppers, the adidas Kids' X CrazyFast .3 Firm Ground Soccer Cleats will help keep young players comfortable on the pitch. The synthetic outsoles offer nonremovable studs, including additional forefoot studs, to help offer explosive speeds and reliable traction. used only a handful of times. see photos.