The Longines Master Collection L2.673.4.51.6 is a sophisticated timepiece featuring a 40mm stainless steel case and a black dial adorned with Roman numerals. Powered by the automatic Caliber L687 movement, it offers a 66-hour power reserve. The watch includes chronograph functions, a moon phase display, and a calendar indicating day, date, and month. Protected by a scratch-resistant sapphire crystal, it is water-resistant up to 30 meters. The stainless steel bracelet is secured with a hidden folding clasp. Reference number: L2.673.4.51.6.