Use the protective inner case with or without the battery sleeve.
2,500 mAh battery more than doubles your battery capacity. Press the charging button to start your charge or check the battery level.
The ENERGI Power Case for the iPhone 5/5s is a sleek protective case with a built-in battery, which doubles your standard battery life. So thin, it's hard to believe it packs an additional 9 hours of talk time. It adds only 9mm to the thickness of an iPhone. 2 slim-line cases are included; 1 black, 1 colored (available in Lime, Red and Blue), which slides out of the charging sleeve so your phone remains protected when you don't need the extra charge. Once your phone is charged, simply remove the exterior charging sleeve to reveal a slim-line inner case for traveling light. ENERGI is superior in design, material, quality and construction.