The M18 FUEL 4 1/2" / 5" Variable Speed Braking Grinder, No. 2888-20, from Milwaukee Tool is a battery-powered grinder with five speeds for increased control and RAPIDSTOP brake for enhanced safety. The POWERSTATE brushless motor delivers 3,500 to 8,500 rpm. With tool-free accessory and guard adjustments, users can experience faster accessory changes and less downtime. The M18 REDLITHIUM High Output XC6.0 batteries (not included) deliver 50 percent more power while running 50 percent further than Milwaukee's M18 REDLITHIUM XC Batteries.