Credit card holder

I've tried to look around for some credit card or NFC cards to use it as in back of your phone.
This is simple design for one up to 3 credit cards so you can use it as your wallet.

Printed on:
20% infill with support
ABS or whatever you feel to

After that you can use double side tape or super-glue to stick it on your phone, back cover of the phone as I did or whatever you feel like.