Wireless Bluetooth Hi-Fi Stereo Headphones Headset for Mobile phone w/Rechargeable Li-battery Pair with Bluetooth Stereo Mobile phone.You wont miss any callings when you are enjoying music You can enjoy the wonderful music wirelessly, and you can enjoy music without wire limit.you can adjust the volume Operation distance up to 10M;System: Bluetooth; Carrier frequency: 2.5G;Power supply of headphone: Li-Batteries Bluetooth V1.2, class 2.Working range: 10M;Normal Charging Time :2 hours(approx). Power supply of headphone: Li-Batteries inside, Weight:38 g.package inclued : 1. Manual instruction 2. USB cable 3. charger