1. V4.0 Bluetooth version, available for most of devices with Bluetooth function.
2. Knitted material ,fashion and keep warm with answer the phone in winter
3. Built-in MIC, available for cell phone to transmit the speaking phone to your audio devices
directly so that the user can hand free answering phone up via the device.
4. Built-in Li-ion chargeable battery, charge via USB Cable, long stand-by time
5. Support display receiver battery on bluetooth device