Almost everyone has had a moment during which they could have really used a little extra battery time on their iPhone. MiPow offers two iPhone cases that offer exactly that, the Maca Air Power and Maca 2200 Color Power.
Both cases provide extra battery power for the iPhone 4/4S and feature a slim-fitting design to avoid the extra bulk that comes with other power-providing cases. The Maca 2200 provides a little extra battery power over the Maca Air Power, but sacrifices some thinness for the extra juice. Cutouts in each case allow access to the phone's volume controls.
The cases feature Micro-USB ports, which can be used to charge the cases or sync the iPhone with a computer.
Both cases feature a reflective metal backing, but, as the name might imply, the Maca 2200 Color comes in a larger selection of colors, including purple, black, silver, gold and red. The aluminum plate on the back of the Maca Air can feature custom, laser-etched designs. The top cover for both cases is transparent.