Arduino Pro Micro

This is an Arduino Compatible Pro Micro ATmega32U4 5V 16MHz Compatible Board. The Arduino Pro Micro is a microcontroller board based on the ATmega32U4. It is similar to the Pro Mini, but with an ATmega32U4 on board. The USB transceiver inside the ATmega32U4 means no bulky external USB interface chip is required!
It has 4 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 is very similar to the popular Uno, but much more compact. 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.
ATmega32U4 running at 5V/16MHz
Supported under Arduino IDE v1.0.1
On-Board micro-USB connector for programming
4 x 10-bit ADC pins
12 x Digital I/Os (5 are PWM capable)
Rx and Tx Hardware Serial Connections
Over current protected
Reverse polarity protected
DC input 5V up to 12V
On board Power and Status LEDs
Size33mm x 18 mm x 6mm