The Nano 328P Expansion Adapter Breakout Board IO Shield acts as a breakout board for the 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.

The board offers

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.

You can use this module with Arduino Nano, to buy them click on the name below
Arduino Nano

Features :

1. Compatible with Arduino NANO.
2. All digital and analog pins breakout.
3. Compact size.
4. External power supply current support.
5. Leads all pins out, convenient for wiring and doing experiments.