1The for Qualcomm chip and dual antenna design doubles the transmission range and makes the connection more stable. 2You can enjoy a seamless listening experience even under electromagnetic interference such as gyms, train stations and airports. 3With optimized antiinadvertent protection, you can precisely adjust the volume, skip tracks, play or pause music. 4The bass tuning has strong power, extreme depth and rich layers, while ensuring clear vocals and crisp treble. 5The bluetooth earphones use the material of ABS, so it is stable and has a long service life. Item Type: Bluetooth Headset Material: ABS Chip: ChinaCache Support: A2DP Decoding Receiving Distance: Approx. 10m/32.8ft Headphone Built-In Battery: Lithium Polymer BatteryThe Built-In Battery Capacity: 50mAh The Built-In Battery of The Charging Box: Lithium Polymer BatteryThe Built-In Battery Capacity: 500mAh Specification of The Built-In Battery In The Charging Box: 902030 Working Voltage: 3.7V (3.3~4.2V) Charging Time: =100 HoursMusic Playing Time: >=3 Hours Microphone Sensitivity: -42+-3dB Working Current:2 x Headphone 1 x Charging Box 1 x Charging Cable 4 x EarCap