Just a simple money clip. I wouldn't recommend that you use this unless you carry cash, as it provides the friction required to keep the cards in place. Holds 1-5 bills and about 9-12 cards. 

If you care how your money looks, don't use this every day, because you will wear it down. If you care about having a cool 3D printed thing on you all the time, you know what to do.

Print with PETG if you can, PLA looses its springiness too quickly. I haven't tested ABS or ASA. Have fun!