The Mooer MEP-YC Yellow Comp compressor effects pedal packs an incredibly BIG sound into a very small package. The Yellow Comp optical compressor pedal delivers legendary smooth sound. It features classic optical compressing sound with smooth attack and decay, and preserves the original signal transients perfectly. Features: Volume: Adjusts output volume EQ: Adjusts the tone Comp: Adjusts intensity of compression The pedal switching is True Bypass, so the sonic integrity of your instrument is never lost. Rugged full metal casing and quality switching in a small and exquisite design. Dimensions (HxWxD): 93.5 x 42 x 52 mm DC 9V Centre Negative Power Supply (sold separately)