The ELF&reg; - Ultra Portable Mini Wireless Bluetooth Stereo Speakers for All Devices with Bluetooth Capability + Siri Compatible - 8 hours Playtime (rechargeable battery) / with Built-in Mic for use as a Powerful Handsfree Speakerphone / Amazingly Powerful & Crystal Clear Sound (Black) Play music wirelessly from your smartphone, iPod, laptop, or any other Bluetooth capable device. Bluetooth v3.0 Technology; connects wirelessly up to 33 feet away. Amazingly strong and clear sound with Bass Enhance Technology. Two powerful 40mm Drivers deliver crisp clean sound with deep bass. Long lasting built-in Li-Ion rechargeable battery gives you 8 - 10 hours of playtime. 3.5mm AUX-in port - Don't have Bluetooth? Connect the speaker to any standard headphone/speaker jack. Doubles as a phone speaker: Features a built-in microphone for hands-free calls in the car, home, office, etc.