The universal quick change system allows you to use one mandrel for all sizes of hole saws with the help of two different sized nut adapters that fit most standard hole saws without the need of any additional tools. Progressive tooth design offers a powerful bite and an accelerated chip clearance. Plug removal is easy with a simple angled reinsertion of the pilot bit. Arbor size 3/8 in. Pilot bit diameter 1/4 in. Pilot bit length 3-3/8 in. Includes: 7/8 in., 1 in., 1-3/8 in., 1-1/2 in., 1-3/4 in., 1-1/8 in., 2 in., 3 in., 2-1/8 in., 3/4 in., and 2-1/2 in. hole saws, (7) adapters from 1-1/4 in. to 6 in., (4) adapters from 9/16 in. to 1-3/16 in., 3/8 in. mandrel, 3-3/8 in. pilot bit, washers.