2.4GHz Digital Wireless Indoor/Outdoor Stereo Speaker with Remote Dual Power Transmitter - Black. Audio Unlimited's 2.4GHz Digital Wireless Indoor/Outdoor Stereo Speaker system with Remote Dual Power Transmitter allows you to enjoy your music inside or outside without running speaker wire. This compact speaker is powered by 2.4GHz technology, which guarantees a strong, clear signal up to 150FT away. The transmitter delivers a powerful signal through walls or any other obstacles in your home or yard, truly offering endless installation options. Just plug in your iPod, iPhone, iPad, computer, stereo, MP3 player or any other device that has a 3.5mm or RCA audio output and enjoy high quality music wherever you want.