ADVA SFP/4GU/D1539.77V optical transport equipment Optical Transmission Module

The ADVA SFP/4GU/D1539.77V is an up to 4G Pluggable DWDM I/F, very long reach optical transceiver module for ADVA optical transport equipment. Parts in this range are ordered by their part number rather than by description, because several share a physical format and are told apart only by the number printed on the label. A part of this kind is held as a spare because a failure takes the function it serves out of use until it is replaced, and equipment of this generation is no longer supplied new by the manufacturer. Where a revision is marked, it forms part of the identification rather than being a batch code, because revisions are qualified against particular software releases. Match the part number and revision against the unit you are replacing before ordering. Tech-Star (UK-based, shipped worldwide) supplies ADVA hardware for maintenance and spares holding.