TP-Link TL-SM321B-2 1000Base-BX WDM Bi-Directional SFP Module

TP-LINK´s TL-SM321B-2 and TL-SM321A-2 is designed to work in a pair to create an on-site gigabit fiber communication up to 2km (2,000 meters). With one single-mode fiber, the pair of modules can create a full-duplex gigabit path between your switches, storage devices, and server.