Found this Westinghouse DC cable insulator in an antique shop yesterday. Can't find out very much about them here at Icon or anywhere else for that matter. Only another collector said there were still some on poles still in the Pittsburg area. When I purchased I thought it was all metal and the top section where the cable was at one time was fried. Discovered when I returned home I discovered the top is metal while the skirt and standard 1 inch threads are some sort of porcelain or unglazed fired clay that bricks are made of.