on the metal shield there are different engravings possible:
- special customer only
- developers only (the one i just got)
- Al-thinker version: full FCC info
Note that datasheet is incorrect about pinout, it states that it is a 16 pin board but its not, there are 18 pins
never the less; it has only 2 more GND pads compared to the ESP-12
Datasheet: LINK