Classic quad skate is made of high impact, resistant polymer plastic. The "auto-adjust" system allows the skate to be easily sized as your child grows.• High impact resistant polymer plastic with "auto-adjust" system that allows the skate to grow with the foot • Wheels are PVC 54mm X 32mm, • Bearings are 608ZB speed bearings • Safety strap closure and Ddual toe brake • The boot easily adjusts to four different sizes with just the push of a button