High polish chrome steel races, heat-treated alloy balls, and friction resistant Delrin® retainers help the KwiK Zenith take bearing innovation to new heights. Built and assembled with these premium parts in a clean room free of environmental pollutants, KwiK Zenith bearings offer a continuously smooth and fast roll while maintaining durability under the most extreme loads of roller skating. KwiK Zenith bearings are pre-spun using a high performance oil, making them ready to use right out of the box with no break-in period required. KwiK Zenith bearings are designed to require minimum maintenance while delivering maximum performance. Occasional cleaning and oiling of your bearings is recommended. KwiK Zenith bearings offer open access to the balls and retainer, making cleaning and oiling a much more simple process.