Marathon 4.00-6" Pneumatic (Air Filled) Tire on Wheel, 3" Hub, 5/8" Bearings 4.00-6" wheelbarrow tire. 13" tire diameter. Pneumatic (air filled) tire. Ribbed tread. 3" centered hub. 5/8" ball bearings. Perfect for residential wheelbarrows. 300 lb load capacity. Not for highway use.