PDK Red Expander Boards accomplish complete scalability, built to customize the Red Max and accomplish all of your system needs. PDK's Aux 8 expander is an easy-to-install input/output board built to handle any auxiliary devices for your system. The Aux 8 helps you provide full control or monitoring of up to eight different auxiliary devices. Every expander board includes built-in Ethernet connectivity and self-discovery, simplifying ip configuration and functionality.