ITEM NAME:Metal Skateboard and Longboard Professional 4 Spacers & 10 Speed Washers Bearing Description: Skateboard hardware set includes 10pcs speed washers, and 4pcs bearing spacers Speed washer is made of iron, used to increase speed and promote longer bearing life by reducing friction between the bearing and axle nut and hangar Bearing Spacer is made of aluminum alloy, 10mmx10mm, used to improve skateboard stability and reduce wheel shake, keep bearings parallel, improve rotating speed and precision, reduce bearing wear and tear Fit on almost skateboard/longboard trucks Accessories for longboard, skateboard, cruiser, crooter, etc. Specification: For Washers: Material: Iron Diameter: Approx. 11mm / 0.4in Thickness: Approx. 1mm / 0.04in For Spacers: Material: Aluminum Alloy Size (H x OD. x T): Approx. 10.5x10x1.35mm / 0.4x0.4x0.05inch Package Includes: 10 Pieces Speed Washers 4 Pieces Bearing Spacers Note: Please allow slight size deviation. SKU: DMO0012913319421493.Accessories for longboard, skateboard, cruiser, crooter, etc. Bearing Spacer is made of aluminum alloy, 10mmx10mm, used to improve skateboard stability and reduce wheel shake, keep bearings parallel, improve rotating speed and precision, reduce bearing wear and tear.