Webb Abrasives SBM Standard Sanding Sponge, 2-5/8-Inch x 3-7/8-Inch x 1-Inch Dimensions: 2 5/8" x 3 7/8" x 1" 4-sided medium (60) grit coating: Brown aluminum oxide Use wet or dry; Features Clog Resistant Technology (CRT) Backing material: PU Blue foam (polyurethane), solvent free Foam hardness: Firm, for high removal capacity Firm, yet flexible foam with durable grit on all 4 sides easily adapts to all surfaces, edges and profiles Use wet or dry Features clog-resistant technology