GBICs are hot-swappable input/output devices that plug into a Gigabit Ethernet port to link the port with the fiber-optic network. There are three GBICs available: one for short reach applications, P/N: 15454-GBIC-SX, one for long reach applications, P/N: 15454-GBIC-LX, and one for extended reach applications, P/N: 15454-GBIC-ZX. The short reach, or "SX" model, operates on multimode fiber (MMF). The long reach, or "LX" model, and the extended reach, or "ZX" model, operate on single-mode fiber (SMF).The 15454-GBIC-LX fully complies with the IEEE 802.3z 1000BaseLX standard and operates on MMF optic link spans of up to 550 m in length or SMF optic link spans of up to 5 km. It is fully compatible with E1000-2, E1000-2-G, G1000-4 modules.