About the size of a smartphone, this is the Bluetooth speaker that expands to 2.1" thick to provide an air-filled chamber that improves sound quality. It connects to an Android/iOS device and streams music from up to 100' away via two five-watt drivers and an omnidirectional woofer. When expanded, the speaker’s air chamber amplifies volume and improves bass resonance, producing robust lows, balanced mids, and clear highs. It has a magnetic backing that enables it to secure to a car or other metal surface. A full charge via the included USB-C charging cable provides up to eight hours of power. Graphite or Snow. 5 1/2" L x 4" W x 2 1/2" D. (7 oz.)