This is what the insulator looks like on its side. It is believed that this piece (like all of the other unembossed CD 140's) were made by Brookfield. There are about 4 or 5 purple CD 140s known. The rest were "liberated" from active 600V DC lines serving the heavily traveled "Green Line" subway transit route beneath the city streets of Boston in 1974-1975 by so-called "collectors". They also amassed other unmarked CD 140s in clear and other exotic colors. The DC cables were left bare upon their tinder-dry "crossarms" and quickly started to burn. Thus, causing fires within the "Green Line" subway system (again, Boston!). The result was immediate intoxication of the fumes with many subway injuries. The insulator has **not** exchanged hands since Joe was able to acquire it from an abandoned building in 1974. It is NOT for sale and is shown here with the above reference as information only. Thank you.