The Electro-Harmonix Screaming Bird Treble Booster guitar pedal is based on the classic design from the "70s. Now the boost effect is back to help your sound take new flight. Whether it"s overdriving an amp or just adding some serious bite to your sound, the Screaming Bird stompbox screams nothing but highs. Use the Electro-Harmonix Screaming Bird Treble Booster to make your guitar cut through any mix.True Bypass Up to 20dB of HIGH frequency gain to any amp Center frequency of 1.6KHz to 2.4KHz at maximum volume Tough and compact die-cast chassis 9-volt battery included 96DC-200BI power supply