Here are some extremely unusual tiny glass spool insulators that I got from Europe recently. These look exactly like a CD 1090 but are extraordinarily tiny. These insulators I suspect were used for low voltage use such as indoor phone wiring, doorbells, etc...something with thin, bare wiring that didn't need a larger insulator. Crudely made clear glass and VVNM.Actual measurements are 1/2" X 1/2".I have set it next to an electric fence insulator for visual comparison. First mail to me... $12 + shipping.