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 it reaches full sound potential ( "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 mAApplication: Guitar/UkuleleColour: blackMaterial: ABSSize: 7.5 x 5.5 x 5cmPackage Contents:1 x Sound Opener1 x connection Note: Do not use while chargingOnly the above package content, other are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.