Diablo's, 3-1/2", 20G, Starlock Oscillating Sanding Plates Feature Application Specific Designs That Deliver Maximum Durability And Longer Life In Sanding Applications. A 20-Grit Sanding Plate Aggressively Removals And Shapes Materials. Open-Coat Carbide Grit Reduces Material Build-Up And Clogging For Longer Life. Tool Free Quick-Change Interface Fits Fein And Other Starlock Tools; Also Compatible With Most Non-Starlock Multi-Tools.