TM1637 4-digit 7-segment LED display
Bare 4-digit 7-segment displays usually require 12 connection pins.
Thanks to the TM1637 IC mounted on the back of the display module, this number can be reduced to just four.
Two pins are required for the power connections and the other two pins are used to control the segments.
TM1637 4-Digit 7-Segment Display Specifications