1970s Audemars Piguet "Hobnail" Cal.K2120 Automatic in 18k white gold Water-resistant

A 1970s Audemars Piguet featuring the renowned Cal.K2120 movement in an 18k white gold screw-back waterproof automatic 'hobnail' design. The automatic Cal.K2120 movement achieved an astonishing thinness of just 2.45mm, which was groundbreaking at the time. It has 36 jewels, 5-position adjustment, and a bidirectional winding system, with a 21k gold rotor used to improve winding efficiency. The exceptional craftsmanship and aesthetic beauty make this a remarkable caliber, as expected from Audemars Piguet. The 18k white gold case, finished with a hobnail pattern, is just 6.5mm thick but still features a screw-back design. The dial is also finely finished with a hobnail pattern, showcasing the meticulous craftsmanship characteristic of Audemars Piguet, one of the 'big three' prestigious watchmakers.