U-1931: England
3 3/4" X 4 1/4" (95mm X 105mm)
No markings {found in Wabash Cambs}
Picture courtesy Gene Kingsley |
37/8" X 4 3/8" (98mm X 117mm)
No markings .
Picture courtesy Russ Firth |
This is a Sinclair Aitkin side knob dryspot style where the inner skirt unscrews to allow a wire to pass through. U number assignment from Worldwide Porcelain Insulators 1986 supplement by Marilyn Albers & Jack Tod.