The Symetrix Audio Symnet Symlink 8 Out DSP Network Audio is a digital IO module designed to expand IO capabilities of the SymNet Audio Matrix DSP. This one has some cosmetic damage and a few LEDs are missing but works. If I knew the make and model of the LEDs I would just put them in. My church updated to Bose line arrays so we don't need these DSPs anymore. Unit has been tested and works.