This easy to install mini gbic or sfp mgblh1 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 lh module uses 1310 nanometer wavelength light in multimode or single mode fiber optic cables and can achieve distances up to 500 meters or 40 kilometers depending on the fiber used 625125um mmf 200mhzkm up to 500m 50125um