These are passive optical Multiplexer / De multiplexers which are used at each end of an optical link to combine and separate the optical signals. Passive operation means they require no power
4 Channel CWDM MUX/DEMUX [1270-1330nm]
4 Channel CWDM MUX/DEMUX [1350-1410nm]
4 Channel CWDM MUX/DEMUX [1470-1530nm]
4 Channel CWDM MUX/DEMUX [1550-1610nm]
9 Channel CWDM MUX/DEMUX [1270-1430nm]
9 Channel CWDM MUX/DEMUX [1450-1610nm]