The Extron CM-20BB is a 20-button, four-space Control Module AAP - Architectural Adapter Plate for use with the MLC 104 IP Plus, MLC 206, and MLC 226 IP MediaLink® Controllers, as well as the System 5 IP Switcher. Using the configuration software, the CM-20BB can be configured to trigger relays and issue IR or RS-232 commands. The CM-20BB is available in black or white. It ships with one IR Emitter. Custom engraving is available to label the button functions. There is an extra charge for engraving.