Diablo 5 in. 40 Grit Ultra Coarse Random Orbital Sander Disc with Stickfast Backing and Easy Pull Tabs 50-Pack 5" PSA No-Hole 40 Grit Diablo Sanding Disc Premium ceramic grain blend is a superior quality formulation designed for fast material removal and long sanding life Stickfast backing, an industrial-grade Pressure Sensitive Adhesive (PSA) backing for a strong and secure bond Clog-SHIELD, a proprietary blend of grinding agents that reduce pitch build-up and clogging For orbital and DA sanders in wood, metal, and plastics. Recommended use - fast leveling, shaping, extra heavy removal and stripping.