This Black Box Multipower Miniature Media Converter links 10-, 100-, or 1000-Mbps segments to 100 or 1000 Mbps fiber cabling. An SFP port enables you to use an SFP to link the converter to fiber cable. Choose from multimode and single-mode SFPs. With a single-mode SFP, the media converter supports distances of to 40 kilometers (24.8 mi.), even 80 kilometers (49.7 mi.), depending on the model you order. For extra versatility, you can power the Multipower Miniature Media Converter one of three ways: through the external AC power supply included with each converter, through the optional USB Power Adapter Cable (which plugs into a PC's USB port and is sold separately), or through the optional rackmount PowerTray (sold separately). The PowerTray provides power for up to 18 converters in only 5U of rack space. Rackmount ears are included.