The Longines Master Collection Chronograph L2.859.4.51.6 features a 44mm stainless steel case with a black dial adorned with Roman numeral hour markers. It includes a date display between the 4 and 5 o'clock positions and three sub-dials for chronograph functions: 60 seconds, 30 minutes, and 12 hours. Powered by the automatic Longines Caliber L688 movement, it offers a 54-hour power reserve. The watch is completed with a stainless steel bracelet and a transparent case back, providing water resistance up to 30 meters. Reference number: L2.859.4.51.6.