General description Miniature bearings are made of high-quality steel and ceramic, designed for low noise and long life. The ceramic ball bearings offer enhanced corrosion resistance and typically require less lubrication. Specifically crafted for roller skating, the 608 bearings improve speed, with lighter balls enabling faster spins and reduced energy consumption. Technical specifications Inner Diameter: 8 mm / 0.31 inch Outer Diameter: 22 mm / 0.86 inch Thickness: 7 mm / 0.27 inch Color: Black + White Material: Mixed materials Package Contents: 32 x Bearings Measurement allowed error: +/- 1-3 cm