U-1951: England
3 5/8" X 5 5/8" (89mm X 138mm)
(both skirt and cap) / P.2320 {Bullers}
Picture courtesy Bob Berry |
This is a dryspot insulator where the top unscrews to expose openings inside the skirt to allow a telephone drop wire to pass through the insulator to provide a "dry spot" from rain and decrease leakage loss. U number assignment from Worldwide Porcelain Insulators 1986 Supplement by Marilyn Albers & Jack Tod.