IRIN Overdrive Guitar Effect Pedal with Normal/Compression Modes Toggle Switch Low/High/Volume/Drive 4 Control Knobs for Electric Guitar - ZIP AMP Features: 4 functional knobs(LOW/HIGH/VOL/DRIVE) for adjusting the performance of the overdrive effect. A toggle switch for the adjustment of standard mode and compression mode. With a significant gain, its overloaded sound has a strong sense of compression. Aluminum alloy metal shell, durable and sturdy, lightweight and compact. Mini compact size, portable and easy to operate. Equipped with a non slip silicone pad, easy to install, making the effect pedal non shifting and anti slip during performance. Specifications: Material: Aluminum alloy Input Impedance: 1MΩ Output Impedance: 47Ω Running Current: 9mA Item Size: 108 * 69 * 32mm / 4.25 * 2.72 * 1.26in Item Weight: 253g / 8.94oz Package Weight: 297g / 10.49oz Package Size: 12.5 * 8 * 5.7cm / 4.92 * 3.15 * 2.24in Package List: 1 * Effect Pedal 1 * Silicone Pad 1 * Manual (English) Note: Please use a DC +9V power supply which is positive outside and negative to connect this unit and connect the input and output socket to this unit.