Everything. The case looks like a giraffe's tongue, and giraffes suck.

Just kidding. The case looks fine. I'd briefly wonder whether dropping it on the metal connector at the bottom would damage it, and I'd prefer the battery color match the case, but those are just nitpicks.

What!? Giraffes are awesome...

We have found the metal connector to be pretty resistant. But we have one year full warranty, so if anything breaks for any reason we will send you a replacement immediately. :)

Can you write more about how you provide a warranty? Is it simply guessing x% of the products will fail within the warranty period and set aside some money to cover those failures. Or is it more complicated?

Hmmm, it's actually much more simple than that. We want to provide a good product that makes people's lives better. The warranty is a forcing function.

In my opinion, if we can't make money while ensuring people's CoBattery cases works, we shouldn't be in business.

Hey, I just wanted to say it's cool to see ideology in business. It's relatively rare. Best of luck to you!