Finisar FWLF1631Rxx optical transceivers are Fixed Channel DWDM SFP designed for use in Dense Wavelength-Division Multiplexing (DWDM) links, for up to 120km link lengths and up to 2.7G bit rates. DWDM 160km SFP transceivers are designed for service providers deploying SONET and DWDM networking equipment in metropolitan access and core networks. They are also compatible to Gigabit Ethernet data rate. The 160km DWDM SFP transceivers are RoHS 6 compliant. Basic digital diagnostic features are implemented as described in Finisar Application Note AN-2030. Enhanced diagnostic features are available as described in the DWDM SFP MSA.