NANO V3.0 3.0 Controller Terminal Adapter Expansion Board NANO IO Shield Simple Extension Plate For Arduino AVR ATMEGA328P
This is a terminal adapter for the for Ard uino Nano.
It lables for Ard uino Nano version 3.0,
however you can still use this adapter for the older version
(just have to remember that A0-A7 are in the reverse order).
You can use this adapter to easily hook up for Ard uino Nano to an outside world via hook up wires.