This unit features a 31-band, 2-channel equalizer for precise sound quality adjustment. - Brand: YAMAHA - Model: Q2031B - Number of Channels: 2 - Frequency Bands: 31 bands Power supply has been confirmed, and sound changes have been easily verified. Please understand that this is not a confirmation of operation using instruments. Thank you for viewing. It will be shipped wrapped in air-cushion packaging and packed in a recycled cardboard box.