All new improved version 2 released October 2014 This multi-meter plugs directly into any USB socket and allows you to connect any USB cable into it for charging and data transfer. It displays on screen the voltage, current and wattage which is being output, acting as both a volt and amp meter. All three are shown simultaneously, there is no need for the display to change between what is shown on screen. It is powered inline so no battery is needed, and uses low resistance components with Premium Power Monitor instead - search for B00LZ07BG0.