? Quickly identify charging devices in one second. This 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. ? Built-in intelligent control chip and 10A fuse: provide over-current protection, over-voltage protection, over-temperature protection, over-charge protection, short circuit protection, reverse wiring protection. Ensure the safety of your charging device and vehicle battery. This universal cigarette lighter USB charger is made of high temperature and low temperature resistant materials, can be used in -20 to 60( ? ) working environment. ? 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 fast car charger equipped with colorful voltmeter and ON/OFF switch. When the USB port is not charging, 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. ? This dual QC3.0 USB ports car charger can simultaneously charge two devices that support the QC3.0 protocol at QC3.0 speed. Total power 36W, each port output up to 18W. Some mobile devices do not support QC3.0, this USB car charger fast charge at maximum charging speed your device supports.