This is a ProMag® Double-stack magazine loader for 9mm and .40 Cal pistols.
Save your fingers from fatigue and maximize your trigger time at the range with these easy-to-use polymer magazine loaders from ProMag! Designed for use with single- and double-stack 9mm and .40 S&W magazines with top dimensions of 1-5/16″ x 13/16″ or smaller, these ProMag magazine loaders are built from impact-resistant, fiberglass-reinforced polymer for maximum durability and longevity.