The Milwaukee® Retractable Starter Bit with Large Arbor provides accurate centering in less time when cutting tile, stone and glass. When used with Diamond Plus™;;; Hole Saws they provide lower cost per hole with up to 10X longer life. With the highly durable Retractable Starter Bit, no pilot holes are required. Use it with Diamond Plus™;;; Threaded Hole Saws to increase your productivity when cutting hard, abrasive materials. Large Arbor fits hole saws 1-1/4" and larger.