Piezo Contact Type Pickup AD-35 Applicable Contact Microphone Transducer for Guitar, Ukulele, Violin, Mandolin, Banjo, Cello, etc. Z086_Transducer This is a passive type, so no power supply like batteries is required, but it's a very user-friendly pickup with a volume control. Also, the cable is detachable as shown in the image, which I think makes this pickup very convenient. The pickup is attached with the included double-sided tape and can be used repeatedly to some extent, but the adhesive strength is generally strong, so it may damage the paint when removed if the finish is delicate. If you are concerned, we recommend attaching it to an unpainted area (for example, the bridge of a guitar) or using commercially available double-sided tape that can be repeatedly attached and easily removed. However, please note that we cannot provide compensation if the paint is damaged during use.