<b>Product Specifications</b><br><br> Package Included: 8 x Inline Skate Replacement Wheels<br><br> Wheel Diameter: 70mm<br><br> Wheel Thickness: 24mm<br><br> Wheel Hardness: 82A<br><br> Bearing Inner Diameter: 8mm (but the white plastic spacer inner diameter is 6mm)<br><br> <b>NOTE 1:</b> The white plastic spacer of these wheels is suitable for 6mm axle. However, if you pull out the white plastic spacer, the bearing would be suitable for 8mm axle.<br><br> <b>NOTE 2:</b> Some customers have the 6mm axle, while others have the 8mm axle, so we add the plastic spacer to deal with these two situations.<br><br>