Diablo 3 pack of assorted flat edge sanding sponge block. Flat edge sanding sponge blocks are tear resistant against splinters and nail or screw ends. Diablo's sanding sponge blocks are used for drywall and wood. All diablo sanding sponge blocks have a unique color code to determine grit needed. The assorted sponge blocks and color codes are red for coarse grit, orange for medium grit, yellow for fine grit, green for super fine grit and blue for ultra fine grit.