First, it may be worthwhile to provide a definition of a GMT watch. The term is often incorrectly used to describe any watch with multiple time zone displays, but the GMT watch name really only applies to models that display additional time zones in a 24 hour format.
There are many dual-time watches on the market and many others with 24 hour displays, but in order for a top replica watches to truly be classified as a GMT, it needs to have the ability to display more than one time zone at a time and one of those time zones must be displayed in the proper 24 hour format.

All Rolex GMT-Master watches are GMT watches (as one would expect given the “GMT” in their name) but not all Rolex Explorer II models can be categorized as GMT watches even though they all have the additional 24 hour hand on the dial.
The 24-hour format was certainly one of the prerequisites that defined the GMT watch, but another requirement was that the watch must be able to display two or more time zones. On the first iteration of the Rolex Explorer II (reference 1655 from 1971), the additional 24-hour hand was permanently synchronized with the standard 12-hour hand, only moving across the dial at a rate of ½.
While there are still two distinct hour hands on these watches, the 24-hour hand is nothing more than a prominent AM/PM indicator that can be read on a fixed 24-hour bezel. It wasn’t until the second generation was introduced in the mid-1980s that the Rolex Explorer II gained the ability to function as a true GMT watch.
Since the Rolex Explorer II’s 24-hour bezel could not be rotated, the two-hour hands had to be adjusted independently in order to function as a GMT high quality replica watches. With that in mind, if any of the above statements apply to your particular watch, then it means that your Explorer II is one of the models that include a movement with independently adjustable hour hands.
To use the Rolex Explorer II as a GMT watch, you need to configure it so that your local time or reference time is displayed by the 24 hands and the time at your current location is displayed by the standard 12-hour hand. Your local time will be read in the normal way, with the hour and minute hands corresponding to the dial, while the reference time will be displayed by the position of the 24-hour hand relative to the 24-hour scale on the fixed bezel.