This is a vintage Hemingray insulator # 40, CD 152, embossed with the brand name and number with a gorgeous deep aqua to teal color. The Hemingray 40 insulator is marked, "Patented May 2, 1893". The No. 40 was replaced by the 42 model in 1921. The insulator was intended for telegraph or "personal communications" lines. My father found this antique insulator on an old telegraph line running along an abandoned railroad track more than 40 years ago. The vintage insulator is in lovely condition, with the exception of a chip on the upper rim. (See photos) Embossing is still sharp. Clarity is very nice and the color strong. There are age related bubbles in the glass. The old telegraph insulator measures about 4" tall and 3.75" wide. For More Information: https://www.nia.org/topten/hemi152.htm https://www.hemingray.info/database/detail.php?cd=152