Speed, 5/8″-11 Joint System (SJS) Helps Prevent Gear Damage, Joint System (SJS) technology helps prevent gear damage caused by accidental wheel binding. Powerful 12.0 AMP motor design for increased output power in a more compact tool. Variable speed control dial enables user to match the speed to the application. Labyrinth construction seals and protects the motor and bearings from dust and debris for longer tool life. Electronic speed control maintains constant speed under load. “Tool-less” wheel guard adjustment for easy clamping. Soft start feature for smooth start-ups. Larger and improved carbon brush material for longer tool life.