It isn’t too small, you have to use it. At first, it feels tight, small and too hard. But after a couple of days of use, the leather will soften and it will take the shape after Lumu Power. It will fit absolutely perfectly.
See it here:
This is how natural leather behaves and Lumubag was designed with this in mind. And don’t worry, you won’t break the Lightning connector on your Lumu Power.