SW530 M b

Manual-winding chronograph with a second time zone and cam-actuated two-button operation. Displays hours, minutes, small seconds at 9 o'clock, a central 60-second counter, a 12-hour counter at 6 o'clock, and a 30-minute counter at 12 o'clock (optionally 15 minutes for SW531 M b). Includes a center GMT/24-hour second time zone with quick-set, manual winding, a stop-second feature, 28,800 vibrations per hour (4 Hz), 21 jewels, and a 62-hour power reserve.