Ownmax 4in 1 3.1A Car Dual USB Charger LED Voltage Current Meter Tester / Temperature Adapter Black Design With Double 3.1A USB Output,PTTC Over-Current Protection Can Be Measured Voltage Range,Current Range,Temperature Range,Display The Voltage,Temperature and Current Alternately By Each 20 Seconds Conversion Efficiency:95%,Output:5V 3.1A 2-port USB Car Charger Provides Maximum Speed to Charge Mobile Devices, Tablet and Music Players SimulTaneously on the Trip. This Portable Fast Car Charger charges for Apple iPhone, iPad , Mini, MP3 Players, Samsung , HTC, LG, Tablet, Cell Phone Auto Power Off While the input Current or Output Current is Greater Than The Safety Current,Please Plug Out Will Working Again