The Roller Derby Rocket MDX adjustable inline skates give children the flexibility of an adjustable skate while remaining a good beginner to intermediate skate. The deluxe comfort foam with reinforced ankle support with power straps offers comfort, stability, and a good fit. The reinforced polymer frame is sturdy and will allow for nice strides. ABEC 5 carbon steel bearings will offer a good glide as well. Features: Wheels: 64 Cast Urethane wheel on 12-2 size, 70mm Cast Urethane wheel on 2-5 size, Bearings: ABEC 5 Carbon Steel bearing. Lining Material: Deluxe padded comfort foam, Skate Type: Kids, Wheel Brand: Roller Derby, Wheel Configuration: 64mm - 64mm - 64mm (size: 12-2), Wheel Configuration: 70mm - 70mm - 70mm - 70mm (size: 2-5), Wheel Durometer: 82A, Bearing Type: ABEC 5, Bearing Size: 608 - Standard, Frame Material: Polymer, Closure System: Laces & Strap, Special Features: Adjustable, Bearing Grade: Recreational, Ventilation: Yes, Number of Wheels: 4, Maximum Wheel Size: 70mm, Skill Range: Beginner - Advanced Intermediate, Model Year: 2013, Product ID: 215366