Original vintage oil and gas magazine ad,  KEASBEY & MATTISON COMPANY, of Ambler, PA.  K & M Asbestos Cement Sheets.  Built to last.  K & M Apac Sheets are made of two practically indestructible materials, asbestos fiber and portland cement.  Pictured are the Apac sheets used on the ceiling of the toll entrance and custom office inspection enclosure at the Port Huron, MI, Blue Water International Bridge.  K & M Best In Asbestos.  Old 1955 petroleum industry advertisement.

On the reverse side (see Additional Images tab) is KEWANNEE-ROSS CORPORATION of Buffalo, NY.  The measurable Advantages of Ross Specially Engineered Exchangers.  American-Standard, American Blower, Church Seats & Wall Tile, Detroit Controls, Kewanee Boilers, Ross Exchangers, Sunbeam Air Conditioners. Old 1955 petroleum industry equipment advertisement.

Approximate page size  9 x 12 inches.