It is familiar for most of us that the GMT-Master II and the Explorer II have always been very close replica watches. Although there are a number of small details that separate the two watches, the Explorer II was essentially a GMT-Master II with a fixed stainless steel bezel. Despite their longstanding similarities, the most recent incarnations of the GMT-Master II and the Explorer II, these two models, respectively, are very different watches that reduce the overlap of the Rolex’s two multi-time zone watches. 
The similarities ended in 2007, with the launch of the GMT-Master II, which entirely redesigned Rolex’s original, multi-time zone watch. The watch is still 40 mm in diameter; however it uses Rolex’s “super case” that has thicker lugs and crown guards for a more bold and aggressive overall appearance.
Instead of aluminum, the bezel insert on the watch is made from Cerachrom, the Rolex’s proprietary ceramic compound that is both scratch and fade resistant. Besides, the face of the watch has been refreshed with a new “Maxi” dial and handset that characterizes the watch’s “GMT-Master II” name and 24-hand in green to match Rolex’s company colors.
When the Explorer II was given an update in 2011, the new model was completely redesigned to be its own special watch, rather than just a GMT-Master II with a different dial and bezel. Instead of using the same 40 mm “super case” from the GMT-Master II, the fake Rolex watch uses a 42 mm case that completely sets it apart form the other models that make up the replica Rolex’s sports watch lineup.
The dial and hands of the Rolex Explorer II also received a redesign, to further help visually set the watch apart. For much of the Explorer II’s history, its 24-hour hand was directly borrowed from the GMT-Master II line. Instead of continuing with this trend, the model features a huge, triangular 24-hour hand that is colored bright orange – in homage to the original Rolex Explorer II from the 1970s. What’s more, the dial of the model features the “Explorer II” name in orange paint to match the orange color of the new 24-hour hand. 
Both the Caliber 3186 and the Caliber 3187 movements allow the 12-hour hand to be set independently from the 24-hour hand, enabling the rolex GMT-Master II and the Explorer II to simultaneously display a second time zone. Additionally, both cheap watches have 24-hour bezels for use with their GMT-functions; however the bezel on the GMT-Master II rotates to enable simultaneous access to a third time zone.
Finally, both the GMT-Master II and the Explorer II have brightly colored 24-hour hands that match the watches’ names printed on their respective dials. These details are done in green on it,
The most recent incarnations of the GMT-Master II and the Explorer II are significantly different watches, each occupying its own, unique place within Rolex’s lineup of highly specialized sports watches.