3M SandBlaster Sanding Discs 9425ES, 5 in by 5Hole, 220 grit, 3-Pack. SandBlaster discs are ideal for use on many surfaces, including wood, metal, and fiberglass. SandBlaster discs were designed especially for high speed power tool sanding.The fine (220 grit) sanding discs were specially developed for final sanding. The heavy duty fiber backing is coated with extremely durable Cubitron mineral, which outperforms our conventional sanding discs because it stays sharp, resulting in a more consistent sanded surface and a longer disc life.