The Milwaukee M18 FROP21 Fuel 18v Cordless Brushless Random Orbit Polisher features a 21mm stroke that allows for fast and efficient polishing, while the variable speed control allows you to easily adjust the speed to match the task at hand. The polisher also has a convenient lock-on switch that lets you work continuously without having to hold down a trigger. Features & Benefits21mm orbital function for fast and efficient polishing with a free hologram finish8 position speed dial selection for maximum control and best finishing results90° rotated battery slot with a clearance of more than 50mmDelivering equal performance as corded random orbital polishers to complete polishing and heavy-correctionsLarge ergonomic front grip area with overmold for easy and comfortable handlingLine-lock-out function to prevent automatic start upLock-on function provides more comfortable and less strenuous use when polishingMilwaukee's Powerstate brushless motor and Redlink Plus e