Longines Watch Master Collection GMT L2.844.6.71.2. The Longines Master Collection perfectly embodies the watchmaking expertise and timeless elegance of the winged hourglass brand. This emblematic line has been enriched by exclusive GMT models in 18-carat yellow gold or 18-carat rose gold, each limited to 500 pieces. These elegant timepieces are powered by an exclusive Longines calibre, equipped with a silicon balance-spring and resistant to magnetic fields.