The production of the Day-Date reference 1802 started in 1959. Sporting a smooth bezel it was released in platinum and yellow, white or pink gold. Placed under a spotlight, the pictured example manufactured in 1970 represents an interesting collectors piece due to its extraordinary conservation state, further enhanced by its perfectly preserved shapes and surfaces, together with its originally preserved polished and brushed finished components.The 18 karat yellow gold Jubilee bracelet bears the 6311 reference. The original box and warranty certification render this timepiece highly desirable for a discerning collector.The 1556 movement was introduced in 1965 and featured a 19'800 beat per hour frequency replacing the previous 1555 mechanism. Since 1972 the movement was further improved by means of a hacking mechanism, which allowed a precise time-setting of the timepiece.