4 Channel Fiber CWDM with LC connectors (1270nm - 1330nm). The OCM 1841 is compact CWDM passive 4 channel optical multiplexers / demultiplexers designed to send and receive up to 4 individual signals over a single fiber link. Each module has an UPG (Upgrade) port to cascade into the other 4 channel modules, expanding the capability of the system to a maximum of 16 channels. The modules can be used standalone or integrated into the optional RFR 1018 1/2 RU 19” rack frame, which can accommodate all four modules. Ideal for system installations.