Shank Arbor With High-Speed Steel Pilot Drill Bit. 7/16" Shank, 1/2" Minimum Chuck Size. Use With 1-1/4" - 6" Hole Saws. The Best Arbor In The Industry Ensures A Solid Connection Without Any Gaps or Wobbling. Arbors Include Replaceable, High-Speed Steel Pilot Drill. Pilot Drills Have Unique Split-Point Tip Design. Use With Greenlee Bi-Metal Hole Saws, Recessed Light Holesaws and Carbide-Grit Hole Saws (Carbide-Tipped Pilot Drill Sold Separately). Can Be Used With Greenlee #901 or #904 Bit Extensions