This is an add on accessory for the DS transforming it into a guitar for use with Guitar Hero games.
The Guitar Grip plugs into the Game Boy Advance slot at the bottom of the Nintendo DS system. Players put their hand through the strap of the Guitar Grip for a firm hold on the system, and then position the system in its vertical book form. The peripheral has a storage area for a specially designed stlyus pick, which is used to strum the guitar strings on the touch-screen. As the notes slide down the screen, players strum the strings while pressing the corresponding fret buttons, all to the rhythm of the song that's being played.