The DW849 DeWalt Heavy-Duty 7"/9" Electronic Variable Speed Polisher has a powerful 8.0 Amp, all ball-bearing construction for long life. Speed is controlled in 3 ways: 1 - user can set the maximum speed from 1,000 to 3,000 with the conveniently located variable speed dial; 2 - the variable speed trigger allows the user to instantly control the speed from 0 to the dialed setting; 3 - an electronic module maintains the specified speed even under load conditions. This drill is durable and easy to service with external brush caps and a spindle lock for easy pad changes.