RS-485 is a cost-effective solution in serial communication networks. It can be used up to data rates at 10 Mbit/s or distances up to 1200m at lower speeds. This RS-485 Shield is a standard add-on board for Raspberry Pi. It is integrated with simple screw terminal as well as DB9 interface.
This module do not contain a Raspberry Pi, if you need one please check here
This is the wiki page for this product, which will show you how to use the product, as well as details about the software and hardware.