here is what I could find on this model.
The watch combines a 44mm case in black DLC with a black obsidian dial and contrasting white and yellow details.
The black dial is crafted from obsidian that is left in its natural form without any treatment and has been hand polished. This distinctive material makes each watch different from the others.
Black obsidian is a natural volcanic crystal that was used in ancient Mexico for the creation of amulets and jewelry. The Mayans and Aztecs knew him as "the god of stone" and used him as a good luck talisman.
The new Montblanc 1858 Split Second Chronograph Limited Edition 100 also offers a textured background for the chronograph indications. This is combined with white hands and numerals, as well as yellow details that provide high readability.
The new Montblanc watch is equipped with the Manufacture MB M16.31 hand-wound monopusher chronograph caliber, which is produced in the Villeret Manufacture.
This complex mechanism makes it possible to measure intermediate intervals without interrupting the ongoing measurement for a longer elapsed time.
If you could get from MB the press file and others photos, it will be nice.