The little card holder to slip your transport card into!
(beyond number 14: the articles no longer have a frame for the photo)
In Paris it will be perfect for the Navigo Pass or the Velib' card & for other metropolises or urban areas your public transport cards.
Obviously this also works for parking cards or other office passes.
Regarding contactless payment cards, this is also ideal because of course leather is a natural conductor so there is no need to take out the card each time.
Moreover, the dimensions will only tolerate one single card in order to maintain it properly.
Each photo corresponds to a unique model.