This 20x44mm vintage 1940s Gruen doctor’s watch is known as the ‘Techni-Quadron.’ These watches were essentially the same as the Rolex Prince and houses the Aegler manual winding extremely fine movement, which is interchangeable with the Rolex Prince. The dial retains the original raised gold-toned Breguet style numerals with only the printing restored. The hands are original. The gold-filled case looks fantastic overall. The movement was just cleaned and is accurate. These watches are highly sought after.