[Upgraded] Designed with the latest on/off contact button, 12V/24V 2 port USB car charger can control the USB charging ports and LED voltmeter together, which saves you the hassle of repeatedly plugging and unplugging the charging cord and helps you protect your battery. [Dual USB Car Charger] Two USB charging ports with a single 2.4A output (total 4.8A) allow you to charge 2 devices simultaneously at high speed. In addition, the built-in intelligent charging IC automatically detects the current and power demand of your devices, then charges your devices at an optimal speed, protects your devices from overcurrent and heat. [Digital LED Display] 12 volt car USB port equipped with a built-in blue LED voltmeter that can monitor the vehicle battery and let you know the battery health while driving, then avoid abnormal voltage problems. [Waterproof] It is designed with a rubber USB cap that allows it to be waterproof and dustproof, better protects its internal circuit and effectively