Bosch HB19EL 19-Piece Electrician Bi-Metal Hole Saw Set Pilot bit easily snaps into mandrel for wood and metal applications Threadless design prevents seizing up in the mandrel Positive lock design to minimize wobble Easy plug removal Plastic case Set Contains: (8) hole saws: 7/8-inch, 1-3/8-inch, 1-3/4-inch, 1-1/8-inch, 2-9/16-inch, 2-inch, 3-inch and y 3-5/8-inch; (5) adapters 1-1/4-inch6-inch; (3) adapters 9/16-inch1-3/16-inch; 3/8-inch mandrel; 3-3/8-inch pilot bit; washer