Lemonbest Dual USB 3.4A Car Charger Adapter with LED Screen Display Digital Voltmeter Monitor for Car Truck, Smart Low Battery Alarm 2 USB output port (5V/2.4A & 5V/1A) charge your Cell phones & Tablets simultaneously at full speed Blue LED screen to display charging status; Smart vehicle battery voltage meter Considerate low voltage alarm: When the voltage is below 12V or above 24V, the Red light will light up with an alarm 90 degree swiveling head pivot, flexible and convenient angle adjustment, perfectly fit for any car cigarette lighter With original smart IC, over-charge and short circuit protection