N-TBD: United States (USA)
3 7/8" X 4 7/8" (99mm X 122mm)
No markings
Picture courtesy Bob Berry |
3 7/8" X 4 7/8" (99mm X 122mm)
No markings [base view]
Picture courtesy Bob Berry |
3 7/8" X 4 5/8" (99mm X 118mm)
No markings
Picture courtesy Ben Kirsten |
These insulators are made from Lignam Vitae, a very hard, heavy and oily wood and were made for use on the San Francisco trolly feeder lines.