4" Diameter 2 ply of non-woven nylon abrasive discs are sewn together to give extra abrasive action! Use without compound to create a bright satin finish on most metals in one step. Also can remove old finishes, rust & corrosion. Perfect for metal wood or masonry. Mandrel mounted on 1/4" hex shank for quick changing between grits. Available in coarse, medium or fine. Made in USA.