cal. 2871 finely engraved manual winding nickel lever movement mono-metallic compenssation balance rotating within a one-minute tourbillon carriage adjusted to heat cold and 5 positions 19 jewels • skeletonized silvered dial Arabic numeral and baton indexes aperture to reveal the three-armed tourbillon carriage with constant seconds mounted atop • platinum rectangular case down turned lugs sapphire crystal display back secured by 4 screws • case dial and movement signed • with a platinum Audemars Piguet buckle