The BOSS BP-1W is a booster/preamp effector with adjustable level and gain. I am selling it to declutter. Operation has been confirmed. Please purchase after understanding the photos and description. For those who can rate the item on the day of arrival, and those who can communicate well via transaction messages. [No price negotiations or silent transaction messages after purchase] Thank you. Please note that we do not accept cancellations or returns after the product has been purchased to prevent any trouble.