niceeshop(TM) USB Mini Charger Doctor Current Test Tool Voltage Test Tool Amp Volt Reader, Blue Condition: brand new; Material: Plastic + electronic components; Weight: 15g Size: 5.3x2.1cm/2.1x0.8inch Compact and easy to carry, no additional power supply, plug and play Stable, reliable performance, anti-interference ability, anti-high temperature Convenient measurement of the output voltage of the usb port and the device operating current