The EvoPlus Q9 Bluetooth headset car charger plugs into the cigarette lighter of your car and turns on and off automatically when you start and stop the engine.
After first-time pairing of your phone with the Q9, when the car engine starts the EvoPlus Q9 Bluetooth headset starts charging and pairing with your phone automatically. When the car engine stops, the EvoPlus Q9 Bluetooth headset stops charging and automatically disconnects the Bluetooth connection.
The EvoPlus Q9 is made of an aluminium housing (weighs only 25 g) with symmetrical sloping edges and has built in two USB ports, a Bluetooth earpiece and a charging plug to insert inside the cigarette socket of your car.
The Q9 earpiece is around 9 cm long, while the dual USB ports are both DC 5V and include a 1 A USB port for charging small devices (i.e. smartphones), and a 2.1 A USB port for charging larger devices such as tablets.
The Q9 Bluetooth headset car charger works very simply. There is only a single multi-functional button that is used to answer/end phone calls, as well as to play/pause music. To answer or end a phone call, you lightly tap the button once to answer a phone call and once again to end the phone call.
With the EvoPlus Q9 Bluetooth headset car charger, you can also connect to two phones simultaneously and switch between them smoothly.

As far as the microphone and the speaker in the earpiece, the speaker earpiece volume can go up very loud which is great. The microphone has a sensitivity of -90 decibel-milliwatts (dBm) with a maximum output power of less than 0.1 pico-watts (pW)