... 4.Built-in speaker&Microphone 5.Mute function Features & Functions:* wireless Bluetooth car kit, clip to the steering wheel, user-friendly.* Built ... with full duplex communicationBluetooth interface: Version 2.0, Class 2,Bluetooth frequency range: 2.402 ~ 2.480GHzBluetooth Range: 8 ~ 10M Talk ... .Battery: Lithium Ion 3.7V 900mAHDetail pictures: High quality LCD wireless Bluetooth car kit