The Roofmaster SPREADMASTER gravel spreader has an adjustable gate for an even 36" spread of rock, from pea gravel to 4" ballast. It's easy to use - and two to four times faster than manual labor methods. Constructed of heavy 14 gauge steel, the four-wheel design insures stability. Holds up to 6.5 cubic feet of material. Length: 46" Total Width: 56" Height: 36" Loading Height: 27" Rear Wheels: 10x2.75 Front Wheels: 4.00x8 Smooth Pneumatics with 1" Roller bearings. NOTE: The Roofmaster Spreadmaster is UNIQUE in the Roofing Industry with FOUR wheels. This keeps the rear wheels out of the delivered gravel / ballast. Leaves the roof with a more finished look.