PowerJive USB Voltage/Amps Power Meter Tester Multimeter, Test speed of chargers, cables, capacity of power banks Displays Current (Amps), voltage and capacity (19,999 mah) Perfect for testing how fast a USB cable or USB power adapter charger is actually charging at Can handle charging speeds up to 3.5A (3,500 ma) and 3v-7v Store charging data in memory. Flashes to alert of low or high voltage issues Test using a USB charger, battery power bank or Micro USB Cable. Test your iPhone or Android phone