This is the Jackson Audio PRISM, a multi-function booster. It features buffer, boost, preamp, EQ, and overdrive functions. The appearance is as shown in the photos. There are minor scratches and blemishes, but nothing critical. As you can see in the photos, there is some dirt and dents on the knobs. Operation has been confirmed. No crackling. The sound cutting out when switching the mini-switches is a specification from the beginning. The color of the LED changes depending on the position of the booster knob. I think it's quite excellent as a clean booster. It works great not only for guitar but also for bass. Tone is for treble, and body is for bass side, and they are independent EQs. When using it with a bass, using the left mini-switch, mid or low, and the right switch AMP or TRANS, and adjusting the booster knob and EQ, you can use it with a preamp-like feel. The low-side body seems to affect a very low frequency range, so it's also recommended for use with bass. With a guitar, it can also be a treble booster, a mid boost, and if you want, a low boost. I confirmed the operation with my 9V power cord. The item for sale is the main unit only.