Cisco WS-G5483 1000Mbit/s Black network media converter

Gigabit Interface Converter 1000BASE-T copper GBIC The industry-standard Cisco® Gigabit Interface Converter (GBIC) is a hot-swappable input/output device that plugs into a Gigabit Ethernet port or slot, linking the port with the network. Cisco GBICs can be interchanged on a wide variety of Cisco products and can be intermixed in combinations of 1000BASE-T, 1000BASE-SX, 1000BASE-LX/LH, 1000BASE-ZX, 1000BASE-CWDM, or 1000BASE-DWDM interfaces on a port-by-port basis.

Cisco 1000BASE-T GBIC.
The Cisco 1000BASE-T GBIC (product number WS-G5483) connects a GBIC port to Category 5 wiring using a standard RJ-45 interface. The maximum Category 5 wiring distance is 328 feet (100 meters).