Yantouch EyE Balls is an add-on for the Yantouch EyE Speaker that allows you to physically see the bass of a song and how much bass the song has.
The Yantouch EyE Balls consists of a plastic chamber with micro balls inside it that attaches to the Swiss Horn bass resonant tube of the Yantouch EyE Speaker via a rubber neck extension.
Aside from allowing you to see the bass of a track, the Yantouch EyE Balls also further enhances the timbre of the bass.
                 
The micro balls are around 2 mm big and can be replaced with even bigger balls and different color balls.