AC/DC Switch for Use with Alternative Power Source, 7.5 AMP motor for high output power in a more compact tool (only 4.5 lbs.). AC/DC switch for use with alternative power source. Small diameter barrel grip (only 2-1/2″) for added comfort. Labyrinth construction seals and protects the motor and bearings from dust and debris for longer tool life. Protective zig-zig varnish seals the armature from dust and debris for longer tool life. Thicker coil wires are wound more closely to reduce heat and energy loss. All-ball bearing design and metal gear housing for durability.