Voltmeter Range: DC 3.50-9.99V (resolution 0.01V) Ammeter Range: DC 0.00-3.00A (resolution 0.01A) Capacity Range: 0-99999mAh Power Range: 0-30.00W Current measurement accuracy: ± (0.5% + 2 words) Voltage measurement accuracy: ± (0.3% + 1 words) Font Color: Blue USB cable through does not affect normal USB communication. Function: 1 Screen rotation function: pressing the back button to display the screen will rotate 180 degrees to accommodate two side perspective about the computer when using the USB port and automatic memory for the next boot mode. 2 Power-down memory function: when the module off the accumulated mAh capacity will be automatically stored to the internal EERPOM the next boot capacity will flash to remind the last part of the cumulative capacity until this cumulative capacity of more than 1mAh the last time the data is automatically cleared start counting again. Mobile computing power battery capacity and efficiency: Ah data x output voltage÷Battery voltage ÷ efficiency = mobile power battery Ah (output voltage is typically 5V the battery voltage is generally by 3.7V typically by 85-90% efficiency) 3 Over-voltage reminder: the voltage on the instrument display is lower than 4.7V (charger output shortfall) or higher than 5.3V (such as Samsung 5V2A 5.3V2A charger with cable loss compensation etc.) the LCD will be on Tip arrow flashes to indicate abnormal voltage flicker can not be closed.