The UN 531-22. Chronograph, moonphase, Lemania base movement. Same manual chronograph movement used by PP, Breguet, Vacheron, etc. (Lemania 2310....I believe) ...
watchesbysjx.com " The UN-33 Visible through the back is the UN-33, which is a proprietary Ulysse Nardin automatic movement combined with the patented calendar module – the same calibre found in the 1996 original. The base movement has an interesting ...