WDM Bi-Directional SFP Module Supports WDM Bi-Directional technology, using a single strand of fiber, cost saving TP-LINK´s TL-SM321A adopts the latest standard 1000Base-BX, transmission over a single strand of fiber, with one different wavelength going in each direction. You can extend the network distance up to 10Km with TP-LINK´s Routers, Switches, Media Converters to provide high speed and stability. Standards and Protocols IEEE 802.3z, CSMA/CD, TCP/IP Cable Single-mode Fiber Fiber Type 9/125 um Single-mode Max. Cable Length 10km Data Rate 1.25Gbps Port Type LC Wave Length TX: 1550nm / RX: 1310nm Power Support 3.3V Safety & Emission FCC, CE Environment Operating Temperature: 0℃~70℃ (32℉~158℉) Storage Temperature: -40℃~80℃ (-40℉~176℉) Operating Humidity: 10%~90% non-condensing Storage Humidity: 5%~90% non-condensing