Features:      Dual channels preamp pedal, and each channel with gain and volume controls. The clean channel goes from crystal clear to crisp, and the gain channel provides everything from fat rock rhythms and heavy metal riffs to searing lead lines. Integrated speaker cabinet simulation function; and Independent 3-band EQ: Treble, Middle, Bass. 2 different modes for footswitch operation: preamp on/off or channel A/B. The LED button can switch between channel A/B(Blue/Red), or switch cab simulation on/off.      Specifications:      Input: 1/4" Monaural Jack (impedance: 1M ohms) Output: 1/4" Monaural Jack (impedance: 100 ohms) Power Supply: DC 9V (Center negative)(not included) Working Current: 220mA Item Size: 9.2 * 3.8 * 3.5cm / 3.6 * 1.5 * 1.4in Item Weight: 160g / 5.6oz Package Size: 10.5 * 6 * 5cm / 4.1 * 2.4 * 2in Package Weight: 180g / 6.3oz      Note:      The power adapter is not included. Please use the power adapter whose polarity is positive pole outside and negative pole inside. Otherwise, the product may not work properly.      Package List:      1 * Effect Pedal 1 * User Manual(English & Chinese)