Hamilton H51616731 American Classic Chrono-Matic 50Product Overview The "Chronomatic 50 Limited Model" features an iconic design that catches the eye. It is based on Hamilton's heritage model "Chronomatic Countdown," commonly known as "Chronomatic E," and is being revived in a limited edition of 1,972 pieces. The 48mm oversized case houses the H 31 automatic movement. The "reverse panda dial" and the countdown bezel, which inspired the name of the original model, are adorned with a vibrant red color,