Donner Equalizer Pedal 5-band Graphic EQ Guitar Effect Pedal 1.Frequency Centers:100Hz,250Hz,630Hz,1.6KHz,4KHz. 2.Volume knob for flexible volume adjustment. 3.+/- 18 dB adjustable gain range per band. 4.Whole Aluminium-alloy classic, stable and strong. 5.True bypass .DC 9V Adapter power supply.