Original electrical trade vintage catalog for AMERICAN DISTRICT TELEGRAPH COMPANY.  Main office was located at 155 Sixth Avenue, New York City, NY. Manufacturers of ADT Protection Systems include Watchman Supervisory System, Manual Fire Alarm System, Aero Automatic Fire Alarm System, Sprinkler Supervisory and Waterflow Alarm System, Local Interior Fire Alarm Systems, Burglary and Holdup Alarm Systems. Disbound from a large 1938 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 security equipment library.