Product Description 7" X 5/16" 80 0 Durite Floor Sanding Disc. 100% silicon carbide abrasive with heavy E, F and combination paper backing for quality cut and strength. Consistent performance and value. Pack of 100. From the Manufacturer 7" X 5/16" 80 0 Durite Floor Sanding Disc. 100% silicon carbide abrasive with heavy E, F, and combination paper backing for quality cut and strength. Consistent performance and value. Pack of 100.