"TRIAL B-1" is a level booster specifically designed to increase volume without altering the sound quality. To eliminate sound quality changes when switching ON/OFF, the signal always passes through the high-spec "B-1 Buffer." The "B-1 Buffer" ensures that the B-1 outputs a stable signal that is resistant to sound degradation and external noise. While remaining faithful to the original sound's response, it slightly softens harsh tones and subtly sharpens blurry tones. It's a booster that also possesses the charm of refining the overall sound as a buffer. Velcro is attached to the back. Comes with the original box. I am selling it because I have switched to a multi-effects unit.