Product Introduction The BOSS AD-3 preamp/effector enhances the sound of your acoustic guitar. Designed specifically for acoustic guitars: It brings out the depth and natural resonance unique to acoustic guitars. Multi-functional: Equipped with a high-performance anti-feedback function, reverb, and chorus, making it ready for live performances and recordings. Convenient features: Practical functions are included, such as the "ANTI-FEEDBACK AUTO" switch that automatically suppresses howling, and the "2x2 CHORUS" mode that spreads the sound left and right. Connection terminals: The OUTPUT can be switched between guitar amp (G.AMP) and mixer/PA direct connection (LINE). Appearance: The control panel on the top is relatively clean (image 1). There is a slight paint chip on the upper right corner of the unit (image 1). The rubber feet on the four corners of the back are present, but there is some wear and tear (image 2). The inside of the battery box is also in a clean condition (image 4). Accessories: Unit only (box, instruction manual, AC adapter, etc. are not included). Please note that this is a used item and is sold as-is, with no returns accepted.