This is a card holder wallet based off the popular secrid wallet, it can hold 6 cards and has a spring loaded return lever.

You WILL need felt strips to make this work. I cut some strips from felt pads made for furniture feet. You will have to experiment with the felt to find the correct tension. Felt strips should be about 25-30mm long. The thickness of the felt will vary, i had to shave about half the thickness off my furniture felt pads to get the thickness correct.

Assembly is straightforward. You want to make sure the lever rotates easily on it's axis, if it is tight you should enlarge the hole. I designed this for use with a small tension spring, but it's not required. The spring you can get from a local hardware store. Look for a pack of Handyman Springs, and the smallest tension spring in that kit will work. You will have to cut one of the loops off the spring from the end and bend a new loop up the opposite way. See the picture of the spring lever mechanism for the correct way the spring should look. The bottom piece fits in the case pretty tight. Be sure you're ready to put that in because it's difficult to remove once put in place.