Diameter 6″. Center hole thread size: 5/16-24 EXT. Low profile allows for better power transfer from the tool to the work surface. Soft density pad provides flexibility to reduce loading. 15-degree tapered edge is ideal for final finishing on flat or contoured surfaces. 3M Stikit attachment provides excellent backing support and easy reuse, optimizing disc life. 5/16-24 external threads are compatible with orbital or random orbital sanders. New one-piece threaded shank for low vibration and improved balance.