600mAh ports tery 10 hours of continuous talk and 500 hours andby after fully charged. The built-in digital power amplifier greatly increases the volume and sound effect. Automatic connection: the car ser is equipped with a vibration sensor, the door is opened, it switches to the auto power and automatically connect to your phone. Automatic switch can save effort and worry while riding. Easy to install and use, clip this ser on your visor, very simple. One click to answer calls, double click to redial, it frees hands and also ensures driving. Server can display income call number and ports to broadcast voice from GPS mobile and music. With multi-point connection technology, it can connect 2 mobile phones at the same time and online, a great replacement for your car's built-in Bluetooth. Bluetooth Car Speakerphone with Visor Clip Kit Wireless Speaker Music Player Car Speaker for Hands-Free Calling, Durable Black