Oris watch big crown complication pilots need resilient and exceptionally readable timepieces oris big crown complication is such an instrument the watch is equipped with oris 581 automatic calibre a modification of eta 26882671 the movement performs 28 800 vibrations per hour and has 17 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 the watch comes with a second time zone and a moon