This is a standard BOSS bass compressor. It allows for a wide range of sound creation, while also making it possible to create punchy, thick, and powerful sounds that take advantage of the compressor's character. It also works well with a guitar. I purchased it new and am selling it because I haven't used it much lately. It's a used item, so there may be some signs of use or scratches, but overall, it's in good condition. Velcro is attached to the back, but it's professional-grade tape, so it should securely attach to your board. The box is included, but the manual is not. The following is quoted from Soundhouse: ■ Bass Effects Pedal ■ Compressor ■ Indicators: CHECK indicator (also for battery check), Gain Reduction indicator ■ Controls ・THRESHOLD ・RATIO ・RELEASE ・LEVEL ■ Input/Output ・INPUT ・OUTPUT ・DC IN ■ Power: 9V battery / AC adapter (sold separately) ■ Accessories: Warranty card, instruction manual, leaflets (Safety Precautions, Usage Precautions, Service Contact), 9V battery *connected to the main unit ■ Size: W72 x D129 x H59mm, 450g BOSS's unique "MDP" (Multi-Dimensional Processing) technology provides a full-fledged multi-band compressor with simple operation. The natural compressor that doesn't lose the fundamental tone and overtones is attractive.