zowaysoon PJH-RS-0377 Car Digital Voltmeter Dual USB 2 Port Power Socket Three Hole Panel, Black USB socket I power output:DC 5V 1A; USB socket II power output: DC 5V 2.1A Indicates charging condition; tells whether your battery is charged or not A high quality voltmeter for checking the state of your battery and battery charger Power Input: DC 12V-24V; output: 5V 3.1A DC(Total) Leegoal bulk packing with good quality warranty