The Milwaukee 2-1/8 in. SWITCHBLADE Selfeed bit drills up to 12% faster and delivers up to 2X longer life. Designed for any trade that demands repetitive cutting of large holes in wood, switchblade bits allow you to remove and replace blades rather than resharpen. You get a new bit with every quick, convenient change of the hardened steel blade, and less downtime on the job. An aggressive feed screw design enables the bit to pull through quickly for faster drilling. Built to last and designed to perform, Milwaukee switchblade Selfeed bits deliver more holes for the money.