Used a few times at the office. It shows some signs of use, but its operation has been confirmed. *Comes with a three-prong power plug. High-quality microphone preamplifier using vacuum tubes, with a digital meter for sound quality adjustment. - Model: MIC2200 - Type: Vacuum tube microphone preamplifier - Input Terminals: XLR input - Output Terminals: XLR output - Controls: Gain, tone, output level adjustment knobs - Features: Equipped with a digital meter - Power: AC power Thank you for viewing.