Fiber Loopback Module is also called optical loopback adapter Or Fiber Optic Loopback Patchcord, is designed to provide a media of return patch for a fiber optic signal, used for fiber optic testing applications or network restorations. Opelink supply various kinds of SingleMode and Multimode Fiber Loopback Module, which are with different connectors including SC, LC, MTRJ etc. Each cable is functionally tested before shipping and is covered by a lifetime warranty.