Kryptonics Formula One bearings. intensive research and testing has resulted in the best bang for the buck bearings. Kryptos formula one bearings are made to exacting specs and are the perfect compliment for any set of inline wheels. Removable alloy shields for easy servicing - Brass retainers for lubricity and speed - Chrome steel SAW 52100 races for durability - Gel lubricant for the best of both grease and oil worlds, low maintenance and speed. Comes with two removable shields for serviceability.