The current batch has problems with Split Keyboards. Add#define SPLIT_USB_DETECT to your config.h in your keymap folder, to solve this issue. If you dont add this, each keyboard half work on it's own, but not if it's connected via TRRS cable.
Running at 16MHz and 5V
Accepts voltage up to 6V(blue board) / 18V(black board)
4x 10-bit ADC channels, 5x PWM pins, 12x DIOs
Related links to "Pro Micro 5V 16MHz - ATmega32u4 controller"