iPort IW22 In-Wall Digital Media System (White) Built-in preamplifier allows variable volume control via IR and RS-232 Delivers long-distance balanced audio up to 500 feet (152m) from the iPort Integrated RS-232 control enables two-way communication (including iPod program metadata) and control of the iPod/iPod touch via compatible control systems Compatible with most dockable iPod models including iPod touch Charges the iPod/iPod touch while it is docked