The 20" 2.1mm DC Barrel to Mini USB 5 VDC Power Regulated Cable provides peace of mind when connected to optional select power solutions. The cable incorporates a voltage regulator that accepts between 5 and 19 VDC and converts it to 5 VDC compatible with USB power. The cable is 20" long and polarity tested so you don't have to worry about crossed polarity when powering devices. Made in USA.