At Baselworld 2018, Tudor created a veritable buzz when they introduced a GMT function to their famed Black Bay diver. The 79830RB comes in a polished and satin-finished steel case that is 41mm in diameter with a screw-down winding crown, a domed sapphire crystal and a solid case back. It has a steel bidirectional bezel with a matte blue and red aluminum disc insert which features 24-hour graduations. It comes with a black dial with index hour markers, steel hands, and a red GMT hand. The 79830RB is powered by the self-winding MT5652 caliber which has a date and GMT functionality with a power reserve of approximately 70 hours. The case is paired with a steel Rivet bracelet with a fold-over clasp. It has a water resistance of 200 meters (660 feet).