Fiber Optic Device HTB-1100S-25Km Fast ethernet 10TXTO 100FX COVERTER Ethernet: IEEE 802.3 10 Base T/10 Base-FL Converter, ST ConnectorMulti-mode Fiber (2km) / Single-mode Fiber ( up to 25km) Fast Ethernet: IEEE 802.3u 100Base-TX/100Base-FX ConnectorMulti-mode Fiber (2km)/Single-mode Fiber(up to 100km) Gigabit Ethernet: IEEE 802.3z 1000Base-TX/1000Base-SX ConnectorIEEE 802.3z 1000Base-TX/1000Base-LX Connector