Auto MDI/MDI-X means you never need to worry about what kind of cable to use.Easy to install. Just plug and play.Compact size.Use inexpensive CAT5e twisted-pair cable on the copper side. Bring fiber to the desktop more conveniently and at a lower cost than installing fiber NICs. Black Box Multipower Miniature Media Converters make it easy to bring fiber to the desktop. Just connect a Miniature Media Converter to your PC's copper port with a CAT5 cable, then connect a fiber cable to the converter's other side. That's all there is to it! Best of all, you can tuck these tiny converters unobtrusively behind your PC. Choose from multimode and single-mode duplex fiber versions. For extra versatility, you can power the Miniature Media Converter through the external AC power supply included with each converter or through the optional rackmount PowerTray (sold separately).