This dual QC3.0 ports car charger supports fast charging of two devices simultaneously at QC3.0 speed. Total output 36W, each port output up to 18W. Please note that some mobile devices do not support charging at QC3.0 speed: This car charger fast charge at maximum charging speed your device supports. This car charger adapter equipped with colorful voltmeter and ON/OFF switch. In the non-charging state, the colorful voltmeter displays the real-time voltage value of the car battery. In the charging state, the color voltmeter does not display the voltage value, it will flash and rotate to indicate the charging rate of the device. You can press the ON/OFF switch lightly, color voltmeter stops flashing and turning. At this time, car charger red indicator light is on, and the car charger USB port can still charge the device. Long press the switch about two seconds, the power of the color voltmeter and USB port is turned off. You can touch the switch again to switch the car charger back to working state. This car phone charger is made of high temperature and low temperature resistant materials, can be used in -20 to 60( ) working environment. Built-in circuit control chip, escort your charging safety. The universal car charger adapter provides the fastest possible charging for all non-fast charging devices. Built-in high-quality spring, easy to plug & unplug. Compact body design, perfect fit with most car cigarette lighter socket.