These are modular card trays designed to hold Settler of Catan cards. You can snap them together to keep the trays from sliding apart. For storage, they stack on top of each other (with or without cards inside) and are easily held together with a rubberband.
This should fit any other cards that are 80mm x 54mm or smaller. I will hopefully have time to expand the design to work with cards of other sizes (Dominion) as well.
I just added a lid part incase you want something to protect the top of the cards while in storage.
Be sure to check my other designs for more Catan parts!
I made these with ABS filament