Used and in excellent condition, the Keeley 4 Knob Compressor Effect Pedal delivers studio-grade compression with warm, transparent tone and exceptional sustain. Ideal for guitarists seeking refined dynamics and responsive control, this hand-built pedal features four easy-to-use knobs: Sustain, Level, Attack, and Clipping. The updated 4-knob design allows for highly customizable compression, letting you dial in anything from subtle limiting to classic squash. Built in the USA with top-quality components, it operates on a standard 9V power supply (not included) and features true bypass switching for pure signal integrity. Whether you're enhancing clean tones or maintaining punch during solos, this Keeley compressor offers the legendary performance trusted by professionals.