NEW Roller Skate Wheels And Trucks 40mm MPC Urethane Wheels with Aluminum Truck for roller skates, skateboard or do-it-yourself project. Cast aluminum trucks with 4 1/4” axle. Many available parts here. Remove the wheels or use as is. Wheel hardness or density is unknown. Please see photographs as they will serve as my best description. Single sale includes 4 trucks and 8 wheels with screws and nuts. Looking for a larger quantity...please contact me for an even better price per unit!!!! Many, Many, Many are available.