Mophie has the 3 Juice Pack cases for the iPhone 5:
- Air: 1500 mAh battery
- Helium: 1700 mAh battery
- Plus: 2100 mAh battery
I've personally used the Juice Pack Air and Helium. The Helium is the lightest and narrowest. I'd say that it's also the thinnest, but I honestly can't notice the difference in thinness between the Helium vs. the Air. The Helium is a bit narrower and lighter than the Air. The Helium has cut-outs for the sleep/wake and volume buttons. The Juice Pack Air and the Plus have button overlays which are easier to press.