This easy-to-install Mini-GBIC (or SFP) module provides a simple way to add Gigabit functionality to your Linksys switch. Gigabit fiber is often used to connect two switches together. The technology used depends on the distance between the two switches.The SX module uses 850 nanometer wavelength light in multimode fiber optic cables, and can achieve distances up to 220 or 550 meters, depending on the fiber used.