Bluetooth/Hands-free phone calling/USB/MIC Noise reduction technology. ? Using the latest Bluetooth 4.0 technology, support for a variety of tablet PCs and smart mobile phones and other Bluetooth devices. ? Soft, clear and dynamic sound all levels clear, Support line-in audio input, provide you with computer speakers can be connected to mobile phone tablet computer and TV wireless pairing playing music? Dual-mode power supply: built-in lithium battery, can be used via USB interface, power supply, or use DC5V USB power supply, dual power supply mode free choice.