COOLMUSIC Compressor Effect Pedal True Bypass Guitar Effect Pedals with 4 Rotating Knobs and Foot Switch for Electric Guitar Bass Made of sturdy aluminum case, this effect pedal with 4 control knobs and a foot pedal switch is easy to operate and practical e. Perfect accessory for electric guitar and bass. Features: Easy e with 4 rotating knobs, adjust LEVEL/ SUSTAIN/ TONE/ ATTACK. With foot switch, easy to switch on/ off the effect pedal. True bypass is provided. Mini size and lightweight, with ring indicator light. Perfect for electric guitar and bass. Sturdy aluminum case, with reliable quality and great durability. Powered by 9V effect adapter (internal negative external positive, not included). Note: Size and color may be slightly different due to manual measurement and different light conditions. Thanks for understanding. Specifications: Model: C-CS01/ C-CS02 (Optional) Color: Green Material: Aluminum + PCB Circuit: Analog Circuit Footswitch: True Bypass Input Impedance: 470KΩ Out Impedance: 1KΩ Output Noise Level: <10mV Current Input: <150mA Input/ Output: 1/4″ Monaural Jack Power Supply: DC 9V Center Negative Regular (Not included), >300mA Item Size: 112 * 58 * 19mm / 4.41 * 2.28 * 0.75in Item Weight: 200g / 7.05oz Package Size: 13 * 7 * 5cm / 5.12 * 2.76 * 1.97in Package Weight: 250g / 8.82oz Package List: 1 * Effect Pedal 1 * User Manual