Guitar Tone Completer Sound Opener Simulates Vibration Playing Guitar The tone completer has the guitar world buzzing! Simulates the effects of actual playing to bring out the best in your guitar. This revolutionary "play-in" simulator is based on the observation that the more an acoustic instrument is played, the faster it reaches its full sound potential (its "play-in" period). The tone completer applies direct vibration to a guitar at controlled frequencies, to the effects of actual playing. Many players report increased volume and dynamic range in their instruments after using the device between playing sessions. Built-in battery: 800 mA Application: Guitar/Ukulele Colour: black Material: ABS Size: 7.5 x 5.5 x 5cm Package Contents: 1 x Sound Opener 1 x connection line Note: Do not use while charging Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.