Mode-conditioning patch cords are designed for longwave(1310nm) Gigabit Ethernet applications over multimode fiber. They consist an offset connection of a SM fiber to a MM fiber. There are two MM fibers on one end and one MM and one SM fiber on the other. This patch cords is required with -LX or longwave Gigabit Ethernet transceivers that use both SM and MM fibers. When launching into a MM fiber, the transceivers can generate multiple signals that cause Differential Mode Delay (DMD) which can severely limit transmission distances. A mode conditioning patch cord removes these multiple signals, eliminating problems at the receiver end.