A group of male employees operate various pieces of machinery at Proof Industries. This division of Clark Cable Corporation manufactured hydraulic valves for military aircrafts. Clark Cable Corporation was incorporated for the purpose of manufacturing automotive electrical accessories such as battery cables, ignition sets, ground straps and other allied items which were sold to automotive parts jobbers, wholesale distributors, tire and oil companies and original equipment suppliers to the automobile industry. Clark Cable Corporation was located at 3184 West 32nd Street in Cleveland, Ohio.