Feature:
Microcontroller: ATmega328A
Operating Voltage (logic level)：5 V
Input Voltage (recommended)：7-12 V
Input Voltage (limits)：6-20 V
Digital I/O Pins：14 (of which 6 provide PWM output)
Analog Input Pins：8
DC Current per I/O Pin：40 mA (I/O Pins)
Flash Memory：16 KB (ATmega168) or 32 KB (ATmega328) of which 2 KB used by bootloader
SRAM：2 KB (ATmega328)
EEPROM：1 KB (ATmega328)
Clock Speed：16 MHz

Support USB download and Power
Support for external 5V ~ 12V DC power supply
Support power supply by 9V battery
Support ISP download
CH340G Driver Download link : http://www.wch-ic.com/download/list.asp?id=126 OR http://www.5v.ru/ch340g.htm
IDE for arduino Download link : http://arduino.cc/en/Main/Software

Each of the 14 digital pins on the Nano can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions.
Some pins have specialized functions:
Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data.
These pins are connected to the corresponding pins of the CH340G USB chip.

The Nano is a small, complete, and breadboard-friendly board based on the ATmega328 ( Nano 3.x).
It has more or less the same functionality of the official for Arduino, but in a different package.
It lacks only a DC power jack, and works with a Mini-B USB cable instead of a standard one.

Package Include :
4 X Nano Board