The CMT 791.033.00 is a 1 1/4-Inch-8-MM Bearing. Be sure to keep the black shield right side up to correspond with the bearing rotation during reassembly. Features: * A replacement bearing for CMT Router Bits * Inside diameter: 8 mm * Outside diameter: 1-1/4" (31.7 mm) What"s In the Box: * CMT 791.033.00 1 1/7-Inch-8-MM Bearing