The Longines Master Collection Chronograph Moonphase L2.773.4.71.2 is a self-winding mechanical watch featuring a 42mm stainless steel case and an opaline ivory dial. It includes a chronograph function, moon phase display, and a date indicator via a central hand. The watch is powered by the Longines Caliber L687 movement, operating at 28,800 vibrations per hour, with a monocrystalline silicon balance-spring and a power reserve of approximately 66 hours. The timepiece is water-resistant up to 3 bar and is fitted with a blue alligator leather strap secured by a triple safety folding clasp with push-piece opening mechanism. (longines.com)