Backing plate for mounting and sealing an electrical connector to an intermediate surface

A backing plate, a corresponding electrical connector for mating with the backing plate, an electrical header, and an assembly thereof are described herein. The backing plate has an inner portion having a first thickness and an outer portion having a second thickness that is greater than the first thickness. The outer portion surrounds a perimeter of the inner portion and forms a cavity within the backing plate for acceptance of the electrical header. The backing plate also contains a connector attachment portion configured to attach the backing plate to the electrical connector and an intermediate surface attachment portion configured to attach the backing plate to the intermediate surface.