MTD 640A thru 645A - is a powerful shredder that can handle a variety of materials, including leaves, twigs, and branches up to 5 inches in diameter. It is also equipped with a 240cc Briggs & Stratton engine which provides plenty of power for even the toughest jobs. The MTD 640A thru 645A also features a large hopper that can hold up to 3 bushels of material, making it easy to shred large quantities of material without having to stop and empty the hopper.