The Milwaukee® retractile Starter Bit with massive Arbor provides correct centering in less time once cutting tile, stone and glass. You’ll cut clean, correct holes quicker once you use the retractile Starter Bit with Diamond Plus™ rib Hole Saws. Diamond Plus™ Hole Saws deliver the best-in-class performance and therefore the lowest price per hole on the market with up to 10X longer life.With the extremely sturdy retractile Starter Bit, no pilot holes are needed. Use it with Diamond Plus™ rib Hole Saws to extend your productivity once cutting laborious, abrasive materials. massive Arbor fits hole saws 1-1/4″ and bigger.