The 40ch DWDM MUX DEMUX is designed by FIBERWDM, wavelength fromC21 toC60(1560.61nm~1529.55nnm), in accordance with the ITU-T G.694.1 100GHZ grid, it maximizes the capacity of the C-band range. The 40ch DWDM with 1310nm port is totally passive DWDM device, and support low insertion loss( wavelength ports 3.5dB; 1310nm port 0.8dB).And it conjunct with The DWDM amplifiers and DCM device, the 40ch DWDM transfer system can support a long distance transmission.