Patek Philippe's world-time mechanism carries all twenty-four zones on the dial and changes reference city with a single pusher, hour hand and city ring moving together. This reference is 36mm in yellow gold, its dial centre worked in hand-guilloché basket weave and finished carmine red — guilloché cut by hand on a rose engine, where the regularity of the pattern is the entire demonstration. What matters on examination: the guilloché itself, since hand-cut work cannot be reproduced in restoration and damage to it is permanent; the city ring's alignment and the pusher's action; and the zone display checked against a known time. Confirmed through the desk. Maker: Patek Philippe. Reference: 7129J-001. Available through ELITA's private desk — verification review, discreet handling and storage. Price on request.