ITEM NAME:104PCS Pro Skateboard Bearings Spacers Speed Rings Axle Washers Accessories img *{margin:0;padding:0;.Bearing Spacer is made of aluminum, 10mmx10mm, used to improve skateboard stability and reduce wheel shake, keep bearings parallel, improve rotating speed and precision, reduce bearing wear and tear. Skateboard hardware set includes 100pcs speed washers, and 4pcs bearing spacers.