SJS Mechanical Clutch System Helps Prevent Motor and Gear Damage Powerful 10.0 AMP motor delivers more output and 10,500 RPM for the most demanding applications SJS technology is a mechanical clutch system that helps prevent motor and gear damage by allowing the drive shaft to slip if the wheel is forced to stop Larger cooling fan and blades pull more air through the motor to help maintain lower operating temperature Large flush-mount paddle switch with integrated lock-off tab for more comfortable operation Labyrinth construction prevents debris from penetrating the motor, bearings and gears for longer tool life Clam-shell gear box design for greater durability and easier servicing. Spiral bevel gears for smoother rotations and a more efficient transfer of energy Zig-zag varnish protects the armature coil from dust and debris for longer motor life Spring loaded metal sealed drive bearing is engineered to prevent dust and debris from penetrating drive bearing "Tool-less" wheel guard for more convenient adjustments Includes: (1) Side Handle (153489-2) (1) 4-1/2" Tool-less Wheel Guard (135107-4) (1) Inner Flange (224399-1) (1) Lock Nut (193465-4) (1) Lock Nut Wrench (782424-9)