The Cisco® ONS 15216 Exposed Faceplate Mux/Demux 40-Channel Patch Panel is a standalone unit that contains both a 40-channel optical multiplexer and a 40-channel optical demultiplexer, precabled within the unit's housing. Two models are available: 15216-EF-40-ODD includes the odd-numbered frequencies as defined by ITU G.694.2, while 15216-EF-40-EVEN includes the even-numbered frequencies. The two units can be combined using the Cisco ONS 15216 48 Channels 50 GHz De-Interleaver with Coupler for an in-service capacity upgrade from 40 to 80 channels.