Refined design at only 6.5 lbs. for increased control</br>Super Joint System (SJS) technology helps prevent motor and gear damage by allowing the drive shaft to slip if the wheel is forced to a stop</br>Larger cooling fan and blades to help maintain lower operating temperature</br>Clam-shell" gear box design for greater durability and easier servicing</br>"Tool-less" wheel guard adjustment for easy adjustment</br></br>Product Description</br></br>Makita  4 1/2 inch 10Amp SJS Grinder. Labyrinth construction helps prevent dust and debris from entering the gear box. Spring loaded metal sealed drive bearing is engineered to prevent dust and debris from penetrating drive bearing. Protective zig-zag varnish protects the armature coil by deflecting dust and debris</br><br/>http://www.amazon.com/gp/product/B00BCV57MM