Diablo's, 3-3/8", Starlock Carbide Grit Oscillating Grout Blades Feature Application Specific Designs That Deliver Maximum Durability And Longer Life Grout Removal Applications. The Thin Kerf Carbide Grit Design Aggressively Routs Joints On Floor And Wall Tiles. An Optimized Blade Design Delivers Faster Material Removal In Hard To Reach Areas. Tool Free Quick-Change Interface Fits Fein And Other Starlock Tools; Also Compatible With Most Non-Starlock Multi-Tools.