In order to power this slender gadget, Apple produced this form-fitting 7.55 V, 39.71 Wh, and 5263 mAh battery.

According to the specs, this is just a hair more than you get from this year's almost-pudgy-by-comparison, 5100 mAh MacBook Air 11"—though Apple touts equal battery performance of up to nine hours surfing the net, or ten hours of iTunes video playback.