USB port

The USB port can be used with USB memory drive filled with MP3, WMA, or Real Audio files; unfortunately that means songs purchased from iTunes (the AAC format) won't work. There's also a battery compartment in the bottom; the batteries act as a backup in case you lose power. If you're looking for compatibility with your iPod, Acoustic Research also offers the step-up ARIR600i ($200 list price), which adds an iPod dock to the ARIR200's feature set.