百達翡麗，不銹鋼枕形自動上弦腕錶，配中心秒針，型號3580，1974年製

Reference 3580 was launched in 1972/1973 and remained in production until the early 1980s, available exclusively in stainless steel, with silvered or blue dials and applied white gold numerals. It is one of Patek Philippe's rare automatic watches in steel case and furthermore the only backwound watch in steel. To the best of our knowledge, the present watch has never been offered in public before.