1940s Universal "Aero-Compax" 33mm Stainless Steel Chronograph (Untouched Case)

Universal, "Aero-Compax", chronograph, 33mm dial size, stainless steel,?a very rare and non-polished item, circa 1940s. A special chronograph with an in-dial for storing the time, known as a memento dial, with a special crown at 9 o'clock to control the memento dial at 12 o'clock. The unparalleled fourth dial design is a fascinating example of the originality of Universal, which manufactured many movements as a chronograph manufacturer, and is a masterpiece of great concentration for its 33mm size." This is a rare piece that bears the designation "Chronometer" in "Mileage" specification.