The black dial Jaeger-LeCoultre Master Eight Days (aka M8D) was limited edition to 50 pieces.
One of the delights is discovering the distinctions from the normal Master 8 Day. There is the 'Night & Day' text, vs 'Day & Night' or 'Jour & Nuit' on the sliver dial version. Additionally, the sub-second dial has 30-60 indicators, unique to this version. The engineering is top notch as well, only 50 turns of the crown needed to energize the entire 8-Day power reserve.
Definitely a piece that deserves more wrist-time...


