Powerful 7.5 AMP motor for high output power in a more compact tool (only 4.5 lbs.). Small diameter barrel grip (only 2-1/2in) for added comfort. Labyrinth construction seals and protects the motor and bearings from dust and debris for longer tool life. Lock-on/off feature for continuous operation. AC/DC switch for use with alternative power source. Protective zig-zig varnish seals the armature from dust and debris for longer tool life. Extra large paddle switch for comfortable operation. Thicker coil wires are wound more closely to reduce heat and energy loss. All-ball bearing design and metal gear housing for durability. Rotatable gear housing can be positioned every 90 degrees.