The Nitro 450 Bushel Manure Spreader has a 13 ton capacity. The adjustable conveyor speed (requires optional flow control or tractor with integral flow control) and heavy duty guillotine style end gate combine to offer even spreading of all materials from wet & sloppy to semi-solid to light & dry poultry manure. The box is constructed of plastic boards with stainless steel mounting hardware, while other surfaces in direct contact with the manure are galvanized.