The H-MD-09-xxx-yyy filters are a range of passive 8-channel DWDM protocol transparent Mux/Demux units. They operate with 100GHz spacing and have an additional DWDM Extension port so that additional channels can be seamlessly added to increase capacity. The channels operate in the standard C-band in dual fiber working configuration. The H-MD-09-xxx-yyy has two Monitor ports that tap off 1% of the transmitted and received line signal. This provides the ability to monitor the channel power levels via a connected Optical Channel Monitoring (OCM) device or an optical spectrum analyzer. The H-Series supports the industrial temperature range of -40oC to +85oC (-40°F to +185°F) which gives an extended application range into sites without temperature control.