Use on flexible shafts with Scotch-Brite™ Wheels for better alignment and handling 6 or 8 inch diameter, up to 4 inches in width. Spindle has a 5/8-11 inch internal thread and 5/8-11 inch external thread. In the Box Our 3M™ Spindle Extender Kit 300 includes all the components necessary to assemble a workable configuration for your application. Included you will find: Two 3/8-inch wire spacers Two 1 x 5/8-inch flange adapters One 2-inch OD x 5/8-inch ID washer One spanner nut One spindle extension Our 3M™ Spindle Extender Adapter 30134 adds length to the tool spindle in order to accommodate a larger Scotch-Brite™ Radial Bristle Brush. Use this adapter with a bristle brush that is 1 inch thick and 8 inches in diameter. You Can Count on 3M Abrasives At 3M, we pay attention to every detail of the abrasive process, from discs to tools to all the accessories in between. Our 3M™ 3M™ Spindle Extender Kit belongs to a long line of high-quality abrasive accessories produced by 3M to help businesses like yours operate faster, better and more efficiently.