Arduino Pro Micro ATmega32U4 5V 16MHZ Board
Arduino Micro — Arduino Official Store
DEVMO 2PCS Pro Micro ATmega32U4 5V 16MHz Micro-USB
Pro Micro - 5V/16MHz - DEV-12640 - SparkFun Electronics
With ATmega32U4, running at 5V/16MHz. Supported under IDE v1.0.1. 12 x Digital I/Os (5 are PWM capable). Rx and Tx Hardware Serial Connections.
diymore Arduino Pro Micro 16MHz 5V with 2-Row Pins Header Module Board ATmega32U4 Module Board Micro USB Pro Micro Development Board Microcontroller
KEYESTUDIO Pro Micro Atmega32U4 5V with USB Cable for
Arduino Pro Micro - ATmega32U4 5V/16MHz
Keyestudio PRO MICRO 5V 16MHZ ATMEGA32U4-MU Development Board For
Arduino Pro Micro - ATmega32U4 5V/16MHz