1. Bluetooth version: V4.1
2. Bluetooth good bass sound headphone
3. Sport headset support profiles such as headset, hands free, A2DP, AVRCP/ HSP/ HFP
4. Ergonomic design for the comfort wearing and anti-fatigue
5. Never miss a call auto switching between the musics and phone calls by multi-function button
6. 120 mAh rechargeable lithium polymer battery
7. Fit on your ears properly, do not catch on your skins or collars
8. Extra two pairs of silicon sleeves in two different size (S and L), M size stays on the headphone already
9. Effect range level: Class 2, more than 10 meters