This is the wireless audio system that enables a listener to keep an iPhone handy as a remote control for transmitting music to its speaker, unlike other systems that require an iPhone remain docked. This model's 1 1/2" sq. x 1/4" thick transmitter plugs into an iPhone's 30-pin port and pairs with the speaker up to 50' away. Unlike Bluetooth wireless systems that are prone to ISM radio band interference and deliver muddy, compressed sound, this transmitter sends music over a 2.4GHz radio frequency, providing 44.1KHz CD-quality audio for the 32-watt speaker. Transmitter streams music wirelessly to up to three additional speakers. A paired iPhone controls the speaker's volume and equalizer settings. The speaker's RCA inputs provide connection for a CD player or other audio device; an output provides direct connection to an additional wired speaker. Compatible with iPhone 3, iPod touch 1st/2nd, iPad, and iPad2. Speaker plugs into AC. 8" H x 16" W x 4 1/2" D. (6 lbs.)