Rodent proof pull chain seal for dock levelers. Replaces the standard ring found on most dock leveler pull chains. Rats and mice can squeeze through gaps as small as 3/4" and 1/4" respectively, making the pull chain hole on most dock levelers an easy entry point. The chain serves as a convenient ladder allowing mice and rats to climb right up and into your facility. The Xcluder dock leveler pull chain seal is a solid cast aluminum pull that sits firmly in the pull chain cup, completely sealing the chain hole creating an impenetrable barrier to mice and rats.