The Optical interface card (OC-4B-SDI) is a one stop optical shop. By using a simple key (SFP) you can unlock the card to be anyone of the more then 200 combinations that are available to you.

Insert a dual optical transmitter SFP, then you will have a 2 channel transmission card. Take the same Optical interface card and remove the dual optical transmitter SFP and replace this with a dual channel receiver,
then Norwia’s AutoSFP® technology will automatically setup the Optical interface card as a dual channel optical receiver.