iKKEGOL USB PC Amp Voltage Current Meter Detector Reader Test Charger Doctor Tool (3.5V-7.0V, 0-3A) for Mobile Phone CellPhone Power Compact and easy to carry, no additional power supply Current and voltage loop display, easy to use and practical USB charger can detect whether the target output voltage and current. Stable, reliable performance, anti-interference ability, high temperature Convenient measurement of the output voltage of the usb port and the device operating current