Global Perspective The Oyster Perpetual GMT-Master II was developed for international travel, offering dual-time functionality for pilots and globetrotters alike. Its robust construction and distinctive bezel have made it a symbol of precision and adventure. Dual-Time Function This model, from 1999, features a 40mm case in Oystersteel and yellow gold, with a black rotatable 24-hour bezel and matching black dial. Powered by the calibre 3185 automatic movement, it delivers approximately 48 hours of power reserve. The Oyster bracelet is secured with an Oysterlock clasp for reliable wear across time zones.