4200mah Flip Cover Battery Case Power Pack Charger for HTC One Max (Black) HTC One Max Device Double Dip Flip Case Made from a tough polycarbonate which protects the back of your phone from accidental bumps, scrapes and drops Extended battery for longer hour operation Flip stand on the back of hard shell, so you can watch videos or other media comfortably Unique, fashionable and high-class sliding design