Vojo OneMini Portable Cell Phone Charger and 2800mAh Battery w/ USB connector (green) Built-in 2800 mAh lithium battery Weighs only 0.2 pounds Intelligent control chip prevents overcharging Two blade U.S. (NEMA 1) wall plug connector folds down for travel Portable 2.75" x 1.5" x 0.9" size