This is a full-mode sustainer unit that was installed in a Fernandes APG-85S from the 90s. It was working normally and produced sound before removal. I have also confirmed that the lamp lights up when powered on. The sustainer worked in all modes: Standard, Harmonics, and Mix. The wiring for the rear humbucker pickup and the battery connection were cut and removed, so please reconnect them. Two pickup springs are missing. One control knob is missing. There is rust on the pickup itself and the sustainer switch. Everything in the pictures is included. This is an old item, so please refrain from purchasing if you are sensitive to such things.