This is a protective and durable case for RFID key cards. This design came about when a much-used key card (which was kept on a shared keyring) kept having pieces break off of it from flexing during carrying and use. This case has served its purpose well for years and has proven its durability many times over.

The key card can still be used without removing it from the case and is designed to be essentially a permanent addition to an RFID key card.

More specifically, this is designed for RFID key cards with a particular form factor which I've encountered from a few different brands, for example Honeywell. They tend to be the same size as a US driver's license, slightly tapered on one side to better fit in a wallet, with a keyring hole on one end. If this describes your key card, there's a good chance it will work with this design. However, if you need to modify the design for your particular key card, the source FreeCAD model is included.

Materials:

The pictured case was printed years ago, but I believe it was printed using IC3D red ABS. It has stood up to use and abuse incredibly well over the years with nary a scratch.

This case is designed to be a very snug fit - there is an opening in the bottom to be able to push the key card back out if necessary. If you don't want quite as snug of a fit, I would recommend upsizing the design 2-5% before printing.

As an extra measure of protection, make sure that after you add your key card, you put a lanyard or keyring through the keyring hole at the top. Provided your RFID key card is one of the same types I've encountered (which seem to have a very similar exterior form factor), the hole should line up with the keyring hole on your card and lock the two pieces together.

Originally posted at: [https://www.youmagine.com/designs/rfid-key-card-protector](https://www.youmagine.com/designs/rfid-key-card-protector)