Grace Digital GDI-AQSHR200 Indoor/Outdoor Water Resistant Wireless Speakers with Dual Powered Transmitter (Discontinued by Manufacturer) A pair of wireless transmitter & speakers 150-Feet range Speakers & transmitter work on AC or battery power Connects to stereo, TV, iPod or any MP3 player Expandable up to 10 additional accessory speakers 900 MHz wireless technology for up to 150' foot range to listen to your stereo, iPod, or TV outside on your yard or patio Dual powered (AC and batteries) stereo speakers and transmitter Control the volume via your audio source or directly on each speaker Full range, high powered downward facing speaker for full 3-D audio sound in your room or outside patio Connect the family of Grace accessory speakers to the GDI-AQBLT200's main transmitter