for DEWALT DCB090 14.4V/20V MAX USB power source is durable enough to withstand jobsite abuse. <br/>Able to charge up to 2 small USB compatible electronic devices on/at the jobsite off your 14.4V or 20V MAX batteries when AC power is not available. <br/>This unit allows you to work with all DEWALT slide style battery packs. <br/>It has an indicator that tells you when unit is powered on and ready to charge devices.<br/> Similar to a fuel gauge, it indicates the amount of power remaining in the battery. <br/>Commonly used for: charging mobile phones, charging digital audio devises/MP3 players, charging digital cameras, and charging small electronic devices when power is not available.