... groove ball bearing 1.Open,Z,RS,RZ 2.Little friction torque,suitable for the high speed,low noise,low virbrationSKF ... radial load as well as moderate axial load. With less coefficient of friction, less vibration and noise,less energy consumption, high limiting speed ... , large size range and variations of structure.Detailed Description1) Model Open, Z, ZZ, RZ,2RZ, ...