Gallery 18 is offering a vintage lightning rod insulator. The piece is marked with a D&S diamond logo, which we understand to identify Dodd & Struthers. It's also marked "Patent Pending." The glass ball is 10-sided. It measures 5" tall, by 3 5/8" in diameter. The insulator shows wear and minor loss on ends. Overall, we rate the condition as fair to good. Gallery 18 has several more examples of this lightning rod ball. Condition will vary. Contact Gallery 18 for details.