Vestil Poly-on steel Caster Kit 6" x 2" Transport loads with portable hoppers. The maximum weight capacity is the lowest weight capacity of either the hopper or the caster. Weight of hopper must be considered when calculating usable capacity. Casters are bolted-on by utilizing the factory stamped hole in the fork tubes. The casters are shipped uninstalled to prevent freight damage. Designed to be easily installed on hoppers, Shipped in a box inside hopper preventing freight damage, Casters allow hopper units to be transported without the use of a fork truck, Heavy duty caster construction provides long lasting durable use.