Scotch-Brite(TM) EXL Unitized Disc, 4 1/2 in x 7/8 in 2S FIN, 5 per case High performance and durability for deburring and finishing applications. A layered, durable unitized disc construction. Soft, conformable, flexible 2 density. Abrasive mineral: Fine grade silicon carbide. Color: Gray. MOS: 11,000 RPM