Double USB output, PTTC over-current protectionDisplay the voltage, temperature and current alternately by each 10 seconds.Fixed support helps stabilize the USB car charger.Color: BlackInput Voltage: DC 12-24V (Error of plus or minus 0.2V)Output Voltage: DC 5V (Error of plus or minus 0.1A)Outout Current: 3.1AVoltage Measuring Range: 5-25VCurrent Measuring Range: 0.1A-3.1ATemperature Measurement Range: -20 degrees to 80 degrees (Error of plus or minus 1 degree)Size: 42mm x 78mm x 20mm/1.65" x 3.07" x 0.79" (Approx.)