Chronofighter Oversize Big Date GMT watches are frequently called 'the ultimate chronograph.' The calibre is G1733 automatic bi-compax chronograph. The watch makes 28 800 vibrations per hour. Additional functions include Incabloc shock absorber, 28 jewels and a 42-hour power reserve. The chronograph has seconds and a 30-minutes counter. Other useful functionalities include GMT/second time zone and a big date window at the 12 o'clock mark. Hands mark hours, minutes and seconds.