Hilitchi 2Pcs SCS16UU Linear Motion Ball Bearing CNC Slide Bushing (16mm Inner Diameter) Metal Linear Motion Ball Bearing for CNC,7 Sizes for You to Choose. Model: SC16UU Inner diameter:16mm/6.2'' Overall dimension:44x50x38.5mm/1.7''x1.9''x1.5'' Packing:4pcs