Bluetooth Outdoor Rock Speaker (Grey Slate) - Stereo pair by Sound Appeal Wireless Rock speaker with long range Bluetooth technology 40W High Efficiency Class D amplifier Dimensions: 11.80" x 11.0" x 10.60" (per Rock) comes in pair. One speaker gets plugged into a 110V outlet , then one wire connects the Master speaker to the slave speaker. Can withstand extreme cold and heat without failure or reduced life. Attractive Grey Slate color. Blends beautifully into landscaping. Also available in Canyon Sandstone.