The Smart-AVI FDX-M4U Multi-Mode Quad DVI-D Extender is a transmitter and receiver set that extends four DVI-D signals along with audio and with USB keyboard and mouse signals, and with RS-232 control, by up to 1400 feet over four multi-mode fiber optic cables.

The transmitter connects to a computer by four DVI inputs and by single USB, stereo audio, and RS232 inputs, and it sends the input signals over to the receiver. The purpose of the USB transmission is to enable USB functionality in the receiver, which can thus, in addition to outputting video via four DVI outputs, also connect to a keyboard and to a mouse by two USB outputs. And the entire system can be controlled by RS232.

The system supports resolutions up to 1920 x 1200 WUXGA at 60Hz, and it achieves zero pixel loss with TMDS signal correction. It features plug-and-play functionality and is compatible with all operating systems. It is compliant with all USB 1.1 specifications for keyboard and mouse connections, and it uses universal single link DVI connectors and supports Mac, PC, and Linux DVI. It has a customizable and programmable DDC table for Macs and for PCs. It is compatible with all major KVM switches. And it can be used in a desktop setting or can be 1RU rack-mounted.

The advantages of using fiber optic cables are that they have a capacity to transfer over very long distances without signal loss, they are immune to electromagnetic interference, and they cannot be tapped and are therefore secure.