1This product can measure voltage of the USB power supply equipment with or without load, voltage and current of the USB terminal equipment during work. 2Voltage and current are displayed in turns, simple to use, convenient and practical. 3It can easily measure the output voltage of USB port and working current of equipment. 4Small size and easy to carry, no need for power supply and other ancillary equipment, plug and play. 5Also can detect whether the USB charger output voltage and current meet standards;applied to factory, laboratory and users.