UEB 4in1 Car Charger, 3.1A Dual USB Voltage Current Temperature Tester Monitor for iPhone 6, Samsung S5, S6, HTC Smartphone- Red Dual USB: charge two mobile devices simultaneously Multi-function: display the charging voltage, current, temperature inside the car Voltage overload protection: this fuction can protecte your device from being damaged timely LED indication: bright and convenient for you to read the information about power Fast charging: combined 3.1 amps; 15W; uses smart technology to ensure each device pulls the right amperage. Charger is powered by the vehicle's cigarette lighter