Surface Roughness : Ra 0.2 Torque Capacity : 12x21x5 mm Structure : deep groove Model Number : 6801RS Material : Chrome Steel GCr15 Bearing Material : Chrome Steel GCr15 Ball Material : Chrome Steel GCr15 Bearing Sizes : 12x21x5 mm Bearing Grade : ABEC-7 Inner Diameter : 12 mm Out Diameter : 21 mm Width : 5 mm Lubrication : Greased Bearing Type : Ball Bearing Bearing Characteristics : Running Smooth Welcome to Lingfeng Store