A CD player is an electronic device that can read audio data on a CD. The player reads the data on the disc and decodes it into audio sounds that are then transmitted to the attached speakers or headphones. The CD player feeds its signal to the pre-amplifier, integrated amplifier or receiver, depending on the amplifier system in use. Some CD players offer additional functionality such as in-dash CD changers, remote CD changers and MP3/ WMA/CD-R & CD-RW compatibility. The most common type of CD player headunit conforms to the single-DIN dimension. Some common single DIN head unit features include: removable or rotating face plates, small LCD screens, flip-out LCD screens and remote CD changers.