Dear kcyjtion!
There are four types of WDM boards supported by the OptiX OSN 3500:
CMR2: 2-channel optical add/drop multiplexing board
CMR4: 4-channel optical add/drop multiplexing board
CMD2: 2-channel bidirectional CWDM optical add/drop multiplexing board
MR4: 4-channel optical add/drop multiplexing board
You can choose the type according to your application scenario.
Thank you!