While the original GMT was launched in the mid 1950s and has always had a two-tone bezel (for easy indication of day vs night), it has never had one that was at once both blue and black. But it does now. And the GMT-Master II (Reference 116710BLNR) doesn’t just have a blue and black cerachom bezel, it has a PATENTED blue and black cerachrom bezel.
You see Cerachom (Rolex’s own version of ceramic) was introduced on the GMT first in 2005. And for years, we were told that making a two-tone ceramic anything was impossible. But this year, Rolex has gone an built a mono-block cerachrom bezel by a patented process that actually has the bezel start off as completely blue, and while still porous, add the black colouring. So, this isn’t two pieces of ceramic next to each other, it’s a singular piece, and Rolex is the only brand in the world to produce something like this. It’s so difficult to do that it’s actually patented — via HODINKEE