Darkglass Duality Fuzz Bass Fuzz Pedal Level: Sets the output volume of the affected signal. Blend: Mixes the clean with the fuzz signal. The clean signal remains at unity gain while the volume of the processed one is set by the Level knob, allowingfor fine control of the blend ratio. Filter: Use this variable LPF (low pass filter) to cut or bring up the high harmonic content. Great for fine tuning the perfect amount of presence and edge. Duality: Selects and mixes the fuzz circuits. Set it counter clock wise for the old school saw-tooth shaping circuit, turn it fully clock wise for the modern, high gain one Power Supply NOT Included