This is the VOX amPlug Bass headphone amplifier. Power-on tested. This palm-sized bass headphone amplifier allows you to practice with headphones by directly connecting it to your bass. It runs on AAA batteries, making it compact and convenient to carry around. I've used it a few times. Please check the photos for minor scratches and dirt from use. If it's difficult to judge from the photos, please ask for clarification before purchasing. This is a used item, so please refrain from purchasing if you are sensitive to such things.