Bosch HSM23-PieceM 23-Piece Sheet Metal Hole Saw Set Pilot bit easily snaps into mandrel Threadless design prevents seizing in the mandrel and provides quick change Positive lock design to minimize wobble Easy plug removal Ejector springs for automatic disk ejection (1-3/4" and larger) Set Includes: (10) hole saws: 3/4-inch, 7/8-inch, 1-1/8-inch, 1-3/8-inch, 1-1/2-inch, 1-3/4-inch, 2-inch, 2-1/8-inch, 2-1/2-inch, 3-inch; 3-3/8-inch Cobalt pilot bit; (7) adapters 1-1/4-inch&#8211;6-inch; (3) adapters 9/16-to-1-3/16-inch; 3/8-inch mandrel; springs for hole saws from 1-3/4-to-6-inches