About this item [Red Voltage Display]This car charger outlet builts in digital LED voltage monitor, dispalys the real-time accurate voltage status of your vehicle’s battery for preventing problems caused by low voltage, the red light also makes quick and easy to find USB ports in the dark or at night, and red display is as visible as in strong sunlight. [LED Switch Red Light]Comes with easy to operate on/off high-quality red light power button for energy-saving and devices protection. [Dual USB Fast Charger]Designed with dual USB ports supporting 4.2A fast charge, since its max single output is 2.1A. Built-in smart IC, will automatically detect your devices and simultaneously charging 2 devices at optimal speed, significantly saves charging time. [Multiple Protection]Certified by CE & ROHS with Over-load, Over-current and Short Circuit Protection to ensure charging safety. meanwhile, built-in converse connection protection ensures the circuit won’t be burnt out