Original electrical trade vintage catalog for MINNEAPOLIS-HONEYWELL REGULATOR COMPANY, was located at 2953 Fourth Avenue South, Minneapolis, MN. Mamnufacturers of Con-Tac-Tor mercury switches, where dependable operation is vitally necessary. Offer practically no resistance to the flow of electricity. Disbound from a large 1942 electrical construction materials book, this unique old one page technical specifications brochure would display wonderfully matted and framed. A marvelous addition to your retro electric equipment library. Contains a small amount of residual glue on edge.