Oris bc4 retrograde day has beautiful design and all of the features that distinguish a high quality watch for aviators it is equipped with oris 735 automatic calibre that performs 28 800 vibrations per hour and has 26 bearing jewels a 38 hour power reserve is available for the convenience of the wearer hands and indices are luminous for improved night time visibility a large day and date display is available additional useful features include instantaneous day and date day and date correc