Asymmetric Discs
Irregularly shaped, non-rotationally-symmetric discs with an offset center of mass may also cause damaging vibration if played in computer CD drives, which can operate at a much higher rotational velocity than stand-alone audio CD players. Some irregularly shaped discs work with tray loading CD drives if they include a circular ridge on their underside that centers them on the part of the tray designed to hold 80 mm CDs, if the tray has such a feature.
Read more about this topic: Shaped Compact Disc