Original electrical trade vintage catalog for BENTLEY, HARRIS MANUFACTURING. COMPANY. Main office and factory was located at 999 Hector Street, Conshohocken, PA. Manufacturers of fiberglass sleeving, extra flexible and special treated. Where high heat, excessive current load or possibility of insulation breakdown makes extra protection a necessity. Disbound from a large 1949 architect construction materials book, this unique old one page technical specifications brochure would display wonderfully matted and framed. A marvelous addition to your retro electrical equipment library.