The DWP849X 7 Variable Speed Polisher has a powerful, all ball-bearing construction motor for long life and durability. It has electronic control that maintains specified speed under load delivering the desired finish results. The conveniently located variable speed dial lets user set maximum speed from 0-600/3500 rpm for different materials and applications. It also has a variable speed trigger allows user to control speed from 0 to dialed maximum setting easily.