Original oil and gas trade magazine vintage ad for GRAY TOOL COMPANY, of Houston, TX. Seven Leagues ahead in complete well control design. Grayloc is the first completion assembly to permit the combination of greater strength with less weight in all components. Other pioneering achievements include Releasing Spear, Drilling Swivel with True Apex Thrust Bearing, and Composite Manifold for flow control. This unique 1959 old oilfield petroleum well equipment magazine advertisement would display beautifully matted and framed. Nice graphics.