The Sir-Compre is an optical compressor pedal with a Friedman twist. The compressor controls include volume, treble, compression and a tight knob. The twist is the included wide-range gain knob. This gain control is the mastermind of the Sir-Compre and allows you to shape the overall sound of the pedal from ultra-clean to semi-overdriven. This combination of compression and overdrive delivers epic tone versatility - semi gritty compression, warm compressed overdrive, singing compressed drive, or adding that special channel to your clean amp - it's all here with the Sir-Compre. And the twist is in the same itself!