The JD spiral insulator is truly one of the world's strangest pin type insulators. nicknamed the "marble roller" by lineman, this unique insulator was made by Jeffrey Dewitt in the mid 1930's. These were intended to be a form of special insulator for highly contaminated areas such as adjacent to a steel or cement plant . There were two experimental lines built with these built in the 30's one of which stayed in service for many years in northern Indiana . Only about 15 examples of this insulator design survive today. this insulator is clean and dead mint other then some top conductor groove abrasions . . Asking $1800+ actual shipping cost . (this piece is quite heavy) ----------------------------------------------------------------------------------------------------------------------------------------------------- Please note this insulator makes a great cat toy. Put a small marble or ball bearing in the top and watch your cat get fascinated as it rolls down the upturned spiral groove . our cat will often chase whatever the insulator spits out at the bottom (LOL)

Note: I am managing the sale of Carver Mead and Barbara Smith's porcelain insulator collection. This unit is from their personal collection.