The Pro Micro ATmega32U4-AU (5V, 16MHz) is a microcontroller board based on the ATmega32U4. It is similar to the Arduino Leonardo board and is fully compatible with the Arduino IDE and libraries. The board is also known as the "Leonardo Pro Micro" or just "Pro Micro".

The Pro Micro has a total of 20 digital input/output pins, of which 7 can be used as PWM outputs and 12 as analog inputs. It also has a built-in USB communication, which makes it easy to connect to a computer and program the board. It can also act as a USB mouse, keyboard, or other USB device. The board operates at a voltage of 5V and has a clock speed of 16 MHz.

The Pro Micro board is small in size and its small form factor makes it an excellent choice for projects that require minimal space, such as wearable devices and portable electronics. It can also be powered by external power supply or by USB connection.

Like other Arduino boards, the Pro Micro can be programmed using the Arduino IDE. You can use it for various of projects such as creating your own Arduino based keyboard or mouse, control LEDs, drive motors and so on.

This tiny little board does all of the neat-o Arduino tricks that you're familiar with: 9 channels of 10-bit ADC, 5 PWM pins, 12 DIOs as well as hardware serial connections Rx and Tx. Running at 16MHz and 5V, this board will remind you a lot of your other favorite Arduino-compatible boards but this little guy can go just about anywhere. There is a voltage regulator on board so it can accept voltage up to 12VDC. If you're supplying unregulated power to the board, be sure to connect to the "RAW" pin on not VCC.