Ball-strain insulator, ca. 1920
Purchase a reproduction of this item on VintageMaineImages.com.
Nicknamed the "Johnny Ball," this insulator is made of a composite material containing asphalt, shellac and asbestos.
Strain insulators are used in the guy wires supporting utility poles or radio antennas to break the electrical path and prevent short circuits or grounding.
If you'd like to privately share a comment with MMN staff, please use this form.