This portable Bluetooth 4.0 stereo speaker weighs just 2.5 pounds, which means it'll go wherever you want it to. With two 2.25" woofers and a two-channel Class D amplifier, it's the loudest speaker in its class. The rechargeable lithium-ion battery gives it 25 hours of playing time, the USB port lets you charge devices, and there's a built-in mic for hands-free calls. The guitar-inspired flip cover has a red velvet lining and durable vinyl shell. Features retractable volume, bass and treble knobs, Bluetooth 4.0 technology and a 3.5-mm input.