Makita GA5042C SJSII High Power Angle Grinder, 5" Powerful 12.0 AMP motor delivers more output and variable (2,800 - 11,000) RPM SJSII provides a leaf spring and cam gear drive mechanism that is engineered to reduce vibration SJSII provides a mechanical gear drive to help prevent motor and gear damage Variable speed control dial enables user to match the speed to the application Electronic Controller is a three-part electronic feature designed to provide the required power in high torque applications and increase tool life