How to tell the difference between an Iphone 5 case & an Iphone 5c case?

I'm making phone cases for my friends and I bought an iphone 5 & 5c case but the package didn't say which one is which. How can I tell the difference?

The iPhone 5 has a boxy shape, so the edges of the case will be square and boxy. The Volume buttons on the iPhone 5 are circle shaped buttons on the top left edge.

Th iPhone 5c has a rounded design, to the edges of the case will be round.Th Volume buttons on the iPhone 5c are long and thin rectangle shaped buttons on the top left edge o the phone.

So if the case has long skinny holes for the volume buttons, its the iPhone 5c case. If it has small round button holes, its the iPhone 5