Patek Philippe, model Ref. 2551, is an important milestone in the brand's history of self-winding watches. As the second-generation automatic watch launched in the 1950s following the pioneering Ref. 2526, it responded to the market's demand for a slimmer wearing experience AT that time while retaining the brand's legendary first automatic movement - the Caliber 12-600 AT. This movement is renowned for its outstanding accuracy and reliable winding efficiency.