The Adder CCS-XB illumination module is an accessory which connects to the CCS-PRO4 (sold separately) to communicate via CCS-LED Indicator Lamp cables (4 included). It gives the users the option to have a CCS-LED LED indicator lamp positioned on each screen to identify which screen you are currently controlling. The color and intensity can be adjusted for each screen. A maximum of 10 CCS-LED illumination indicators can be supported.