The RME HDSPe Opto-X Optional Expansion Board is perfect for audio professionals looking to enhance their setup. It works great with the HDSPe MADI FX Triple MADI Card. With dimensions of 3.0 x 5.0' (76.2 x 127.0 mm), it's compact. It adds more I/O ports, has a Word Clock I/O, and D-sub connectors for MIDI and AES I/O. The optical MADI I/O replaces the standard coaxial one, providing an upgraded experience.