The Makita 4-1/2” SJS™II High Power Angle Grinder (GA4542C) combines power, convenience, comfort and motor-protection features for longer-lasting industrial performance. It is ideal for cutting, grinding ferrous metal, paint and rust removal, shipyard maintenance, metal polishing, general steel grinding, auto repair work, cutting brick and masonry, restoration work, and more. The GA4542C is equipped with SJS™II, a mechanical gear drive system to help prevent motor and gear damage by dampening the force on the gear when the wheel is forced to stop. SJS™II is also features a leaf spring and cam gear drive mechanism that is engineered to reduce vibration for increased operator comfort during extended use. The 12 AMP motor delivers 2,800-11,000 RPM for versatility and maximum productivity. Labyrinth construction protects the motor with a complex set of channels, prohibiting dust and contamination from entering the motor. Additional protection features include a zig-zag epoxy applied to both sides of the armature coil, and a powder-coating to the field. This forms a barrier under rotation and is engineered to protect from dust and debris penetration for longer tool life.