This is a page from the 1904 G. E. catalog showing rack insulators to support cables and bus bars for sub-stations, subways, motor and transformer rooms, etc. There were many configurations and sizes to fit any size conductor. [id=450535448] A large variety of these 1-wire rack cleats can be found here: http://www.r-infinity.com/Cleats/Cleat_Photos_1Wire-p1.htm