SFP-Port 1000 BASE-BX (WDM, TX:1550nm) mini-GBIC module - 20km. Single mode. DDM Support. Complies with the IEEE 802.3z Gigabit Ethernet standard. LC connector. Differential PECL inputs and outputs. Single power supply 3.3V. TTL signal detect indicator. Hot Pluggable. Class 1 laser product complies with EN 60825-1. Operating temperature: -40ºC up to 75º C.