Trend Router Cutter Spares B19C - Half inch bore bearing 3/4 inch Diameter x 1/2 inch Bore Key Features: Bearings are shielded to prevent penetration of dust and grease packed for life They should not be cleaned with solvent or lubricated as this will dissolve the grease and cause premature bearing failure Scrape off any resin build-up Always check the tightness of the fixing screw before using cutter Specification: OD: 3/4 inch: (imperial diameter) OD: 19.05 mm (metric diameter) ID: 1/2 inch Thickness: 5/32 inch Bearing Code: R1212-ZZ