These 4-1/2" x 5/8-11" 40 Grit Ovation Flap Discs (78106) from Sait are designed for finishing and blending applications on a variety of aluminum, stainless, and metal materials. They are composed of premium zirconium material and feature a high density design for softer, cushioned grinding, blending, and finishing work. They provide excellent operator control, resulting in a consistent finish with controlled stock removal rates.