SuperTooth D4 Bluetooth Stereo Speaker - Retail Packaging - Stone Grey Instant pairing with NFC technology and Bluetooth version 4.0 Stereo streaming of music files via Bluetooth A2DP profile, from any mobile phone or PC equipped with the same technology Portable product, listen to your favorite music anywhere thanks to its rechargeable battery Superior sound quality, Bass reflex, High efficiency speakers, Can charge from the computer USB Operating range : 10 meters, Frequency : 2.4 GHz