Bluetooth 4.0 Stereo Headphone, Magnet Design Wireless Headset, In-ear Bluetooth Earphone with Mic, With 3 Pairs of Different Size Earbuds, Compatible with Digital Equipment with Bluetooth Bluetooth V4.0 wireless headset :The latest technology of CSR chip and backward compatibility V3.0, V2,1 V2.0 and so on Human ergonomics design : soft and comfortable wearing experience meet your royal taste. Unlimited joint your ear and very suitable for wearing while driving car Stable signal transmission : barrier-free 10 meters transmission distance(depend on the environment) 95 mAh rechargeable battery : About 1.5 hours charging time brings 5 hours music time(The volume will effect the time) Excellent sound qualitywith bass effect, high-fidelity stereo music and clear speech