This is a 40 Channel DWDM Mux and Demux 19inch rack mount with LC connectors and that operates over channels 21-60. This unit can be used as either a multiplexer or de-multiplexer (mux/demux), and is a plug and play system. All of our mux/demux products are 100% compliant and provide a cost effective solution for your network upgrade needs. With our certification test program, we guarantee your product will work correctly the first time.