Boss ... AC-3 acoustic simulator pedal ... has built in Reverb also ... bought used ... very little studio use since i've had it ... now have guitar w/built in peizo , so i no longer need this ... Stock photo .. in great shape .. ! $40 shipped / lower 48 USA / paypal OK some specs ; Effects processor utilizes COSM technology to transform electric guitar input into beautiful acoustic guitar sounds. ● MODE knob allows you to select from a choice of four different acoustic guitar characters (tones). ● Features two types of output jacks, one for guitar amps and another for line out jacks, providing you with outputs suited to the connected device. ● BODY and TOP knobs can be used to adjust the acoustic guitars characteristic body resonance and harmonics, allowing you to produce a wide variety of tones. ● Includes high-quality reverb developed exclusively for the AC-3. COSM (Composite Object Sound Modeling) Composite Object Sound Modeling (COSM) is BOSS/Rolands innovative and powerful sound modeling technology. COSM analyzes the many factors that make up the original sound, such as the electrical and physical characteristics of the original, and then produces a digital model that can reproduce the same sound.