Makita 9557NBX 7.5 Amp 4-1/2-Inch Angle Grinder with Diamond Blade 7.5 Amp motor design for high output power in a more compact tool - only 3.5 lbs. Protective zig-zag varnish seals motor from contaminants by forming a barrier under rotation Thicker coil wires are wound more closely to reduce heat and energy loss All ball bearing design and metal gear housing for durability AC/DC switch for use with alternative power sources