Legion Meter is a device that can safely accelerate your smartphone/tablet's charging speed up to 92%. It also features a built-in multimeter for displaying voltage, current, power, and milliwatt hours on the integrated OLED display. Legion Meter installs in seconds and is fully plug and play. Legion Meter's Watt Hour (mWh) mode is useful for analyzing the storage capacity of batteries. Much like how a gas pump counts the amount of volume of gas that gets pumped into a vehicle's gasoline tank, the watt hour meter measures the amount of energy or (Watt Hours) that gets charged into any battery. This is useful for discovering the true storage capacity of batteries. Press and hold the button to reset the counter to 0.