A grain cart or a chaser bin is a trailer towed by a tractor with a built-in auger system. Grain carts are used during harvest time to transport grain and corn from fields from a combine to another hauling devise. Grain carts allow the combine harvester to unload. These carts are large which mean that they also require large powered tractors to haul them away out of the field. There are a number of different brands and sizes available to choose from. Grain carts are an essential piece of farming machinery needed at harvest time, and large-scale farming operations often require several grain carts.