Mount objects up to 440 pounds on this medium-duty, swivel caster. Designed with a galvanized steel frame with a brake mechanism, and a four-inch diameter sandwich wheel with a 1 1/2-inch tread width. The mounting plate is 3 3/8 inches long and 4 1/8 inches wide with a 5/16-inch bolt diameter. The bolt hole spacing is 2 3/8 inches long and 3 1/8 inches wide.