Here at SparkFun, we refuse to leave
DEV-12640 SparkFun Electronics
Description Features Documents Here at SparkFun, we refuse to leave 'good enough' alone. That's why we're adding to our line-up of Arduino-compatible
Pro Micro - 5V/16MHz
Pro Micro 5V/16MHz — スイッチサイエンス
Arduino Original Boards — Cool Components
What are the Arduino micro and Pro micro board?
Buy Pro Micro - 5V/16MHz - Atmega32u4 module - Botland - Robotic Shop
DEV-12640 SparkFun Electronics
DEV-12640 SparkFun Electronics
Trying to understand Sparkfun Pro Micro design - Other Hardware
Arduino Micro
GitHub - sparkfun/Pro_Micro: ATMega32U4 Arduino board, available
SparkFun - Pimoroni
Buy Pro Micro - 5V/16MHz - Atmega32u4 module - Botland - Robotic Shop
Arduino Pro-Micro, 3D CAD Model Library
Pro Micro - 3.3V/8MHz - DEV-10999 - SparkFun Electronics