This used SP Compressor from Xotic Effects is part of Xotic's mini pedal line. It features a mono 1/4" In/Out with a Volume knob, Blend knob, and a three-way dip switch to select your compressors ratio (Lo, Mid, Hi). It can be powered either 9v power adaptor or a 9v battery.

This pedal is in very good condition with little to no blemishing with some velcro residue left on the bottom.