The Expansion Breakout Board IO Shield for Arduino Nano microcontroller. There are several different options for power input and the footprint of this board is the same as the Arduino Duemilanove.
In addition, each pinout includes 5V and GND pins for easy connection to sensors or servos. The unit comes fully assembled.
 Arduino Nano IO Expansion Shield is specifically designed to facilitate an easy connection between  Arduino Nano and many other devices. In essence, it expands the Arduino Nano controller to link those devices in a simple and trouble-free manner.
It is a perfect companion of Nano breadboard and compatible with both Arduino Nano v2.x and v3.x.
Features :
14 I/O Pin (servo type with GND, power, and signal)
8 analog Pin with power output and GND
6 PWM Pin
1 Servo power input
5 I2C expansion Pin
1 AREF output
1 3.3V output
Package Includes :
1 x Expansion Breakout Board IO Shield for Arduino Nano