Rolly is an egg-shaped digital robotic music player made by Sony, combining music functions with robotic dancing. It has two wheels that allow it to rotate and spin, as well as two bands of colored LED light running around its edge and cup-like "wings" (or "arms" according to the Sony sonystyle USA website) which can open and close on either end, all of which can be synchronized to the music being played. Rolly has 2 gigabytes of flash memory to store music files. In some markets it came pre-loaded with the track Boogie Wonderland by Earth, Wind & Fire.