This is a Behringer limiter compressor. It was acquired from a live music venue. It is a used item. Due to lack of time, only power-on has been confirmed. Sound output has not been checked. The illumination of the two VU meters on the right side does not work. The SCMON knob for channel 2 is missing. This is a discontinued vacuum tube compressor. Operation has not been checked; sold as junk. Please refrain from inquiries after purchase. The internal vacuum tubes do light up. Please refrain from any inquiries regardless of the condition. It will be shipped with air-cushion packaging and corrugated cardboard. Thank you.