Designed for use with an angle grinder, Diablo's 4-1/2 in. Steel Demon Grinding and Polishing Flap Disc grinds and polishes simultaneously to help you scale down and smooth out metal and stainless steel surfaces. Featuring a new Speed HUB design, this flap disc can be changed quickly, without the use of tools. A conical shape and 40-grit (ultra-coarse) composition combine for 10X faster material removal, leaving behind a shiny surface that gives your work piece a revitalized appearance and/or operational resurgence.