DeWalt 9" 6,500 rpm 4.7 HP Angle Grinder No-LkThe DWE4559N Angle Grinder has a high power 4. 7 HP motor with overload protection and 6,500 rpm for optimal material removal with 9" grinding wheels. Dust Ejection System prevents harmful dirst from entering the motor. Additional Features High power 4. 7 HP (maximum motor HP) 6,500 rpm motor provides overload protection provides higher operating speeds under load Dust Ejection System increases brush life and protects the motor from damaging particles