Retractable Starter Bit With Large Arbor, Provides Accurate Centering In Less Time When Cutting Tile, Stone & Glass, Increase Productivity, No Pilot Hole Required, Improve Accuracy, Hard Carbide Retractable Bit Securely Marks Hole Center, Large Arbor Fits Hole Saws 1-1/4" & Larger, No Arbor Needed.