The Mercer 396BLK is a 4-1/2 x 7/8-Inch Silicon Carbide Prep Wheel. Features: * Type 27 shape * Available with 5/8-11-Inch threaded hub * Non-woven synthetic fiber impregnated with abrasive grain * Three different grades What"s In the Box: * Mercer 396BLK 4-1/2 x 7/8-Inch Silicon Carbide Prep Wheel