World's largest manufacturer of computer controlled switching devices since 1995. Our boards mount as a virtual COM port on your computer and can communicate via the USB or RS-232 port, wirelessly, over the internet or with a cell phone. Built with expansion in mind our Relay Boards are expandable to 256 relays and you can control one relay at a time or all 256! With so many options there is only one choice in computer controlled relay. Browse our videos and visit our web site and see why we are the only choice for computer controlled switching.