Sure, it's just an iPhone battery case, but what marks this one out from the many others is the manufacturer: Apple.
The US$99 iPhone 6s Smart Battery Case is the first sign that Apple is ready to acknowledge that its phones are too thin to contain adequate batteries. The case adds 80 percent to the battery life -- and about 100 percent to the thickness -- of an iPhone 6 or 6s.
Unlike most third-party battery add-ons, the back of the case isn't flat, but has a bulge in the middle housing the battery.
Apple claims the iPhone 6s allows you to surf the Internet on LTE for "up to" 10 hours, a figure that could reach up to 18 hours with the external battery. The battery could also boost talk time from up to 14 hours to around 25, while video could play for up to 20 hours rather than 11.
The catch is in the words "up to" -- and Apple is by no means unique in using them: Pretty much every electronic device manufacturer does the same.