The b 42 stratoliner chronograph black is part of the fortis aviation watches collection it is equipped with swiss made valjoux 7750 automatic calibre that performs 28 800 vibrations per hour and has 25 bearing jewels other movement characteristics include fine timing device and incabloc shock absorber numerals indices and hands are covered with luminous paint for enhanced night time readability a date display is positioned at 3 oclock and a day window is available at 9 oclock the watch