Guitar compressor/drive pedal effect. Features: Combines Keeley's Red Dirt Overdrive and Compressor effects in one stompbox. Switch allows you to place compressor either before or after overdrive. High-quality components used throughout. Extremely dynamic, touch-sensitive gain at both low and high gain settings. Input: 1 x 1/4'' TRS. Output: 1 x 1/4'' TRS. True Bypass. Power Source: 9 V DC power supply required (not included) or 1 x 9 V battery.