IWONDER Cloud Wheel 105mm Discovery Electric Skateboard Wheels Patented Damping Foam Core All Terrain Off Road 78A Translucent Urethane Longboard Wheels（Not Applicable to Hub MotorDiameter 105mm Polyurethane(PU) all terrain off road electric skateboard longboard wheels,40% Bigger than normal PU wheel,make your riding unobstructed,the spokes in the core of discovery version is thicker. Patented Damping Foam Core Technology The Cloud Wheel with the damping foam core filters out most of the vibrations than the regular wheel. Curved wheel and unique tread The curved tread design makes the skateboard effectively increase the grip