This CX-2x1-x (MUX/DEMUX) module is optical converter and will convert from two FP laser or CWDM laser wavelength to Multiplexed 1290nm - 1350nm or 1510nm -1510nm range (MUX), or opposite direction (DEMUX) from Multiplexed 1290nm - 1350nm or 1510nm - 1510nm range signal to four FP laser or CWDM laser wavelength. This unit is compatible with all Meridian products as well as many other fiber transmission products in the market.