I came across this streetlight duplex insulator in a auction a while back. What makes it unique is that it's made for A.B., Chance Co. and it's embossed!. Chance usually marked their insulators with an underglaze marking continued from their purchase of Porcelain Products Inc. in 1959. This piece I belive was made at the Carrey plant where P.P. Inc. still made dry processed and embossed standard porcelain spools, nail knobs etc. P.P. Inc. was a subsidary of A.B. Chance company for several years before they became wholly owned by Chance. I've only come across a few companies that made these split spool versions with Line Material Co. and Hubbard & Co. being the most. A really neat piece.