Patek Philippe · Manual Wind

175

A hand-wound Calatrava movement that stayed in production about twenty-five years, derived from the ultra-thin Frédéric Piguet calibre 21. It beats at the slower 2.5 hertz of its generation, which suits a thin movement's limited torque, and is regulated by a free-sprung Gyromax balance. It predates Patek's move to building every calibre in the range itself.