The Datograph Up/Down ref. 405.031 was introduced in 2015, a few years after the initial launch of the Up/Down Datograph (in platinum). It features the new movement with (among other changes) the added 'up/down' power reserve indicator.
Ref. 405.031 features a pink gold case and a black dial with silver subdials.
All 451 parts of the L951.6 manufacture calibre are lavishly finished. The sharply polished reentrant angle of many calibre components is an indication of the amount of work involved: this delicate, time-consuming process can only be executed by hand. The 8-gap column wheel coordinates all the switching operations of the chronograph mechanism. Rockers and levers of various shapes engage with this wheel. The considerable length of the levers is due to the special dial arrangement. They bypass the outsize-date mechanism and bridge the distance to the subsidiary dials located below the center line.