Pro Micro - 5V/16MHz - Atmega32u4 module - SparkFun DEV-12640*
Module based on the Arduino Leonardo, is characterized by small size. It has the AVR Atmega32U4 microcontroller. It is equipped with 20 digital inputs/outputs, as well as popular communication interfaces. It works with voltages of 5 V. This version does not have soldered connectors.