... 4.URB brand 2012 High Precision NSAR 3D Thrust Ball BearingSpecifications1.5110 series Thrust ball bearing 2.high load capacity 3. ... structure,strong rigidityItemThrust Ball Bearings Type uni-directional thrust ball bearing,bi-directional thrust ball bearing Ssries 51100,51200,51300.,52200, 52300 ... .51451,9003,0000.4 2012 High Precision NSAR 3D Thrust Ball Bearings NSAR Thrust Ball Bearings 51107