First off, I love this card holder and use mine every day and have for quite sometime. When it was new and I had only just begin to carry it, it fell from my hand one day when I was removing a card to pay for a purchase.
When it hit the floor most of the remaining cards spilled out of it. Not wanting this to happen again, this is the solution I applied and it hasn't failed me yet.
At the dollar store I found a card of elastic bands women use in their hair and one band fits very nicely over the height of the card case and cards.
A zipper pull makes it easy to move the band off of and onto the cards.

I have been carrying this now for a few weeks as my wallet. I have two cards on one side. The opposite side carries three cards, a wallet knife, and a phone stand. I have had no issues with things falling out. I also use one al work to carry business cards on one side and a reference guide for radio channels on the other.

I just ordered a second. The first wore out. This is an observation, not a complaint. This wallet needs enough cards in each side to create friction to hold them in. The stacks of cards wear through the plastic inside and outside of each pocket. The mesh remains. The wear is cosmetic.
For this price, a cosmetic replacement is entirely acceptable.

So far this little card holder has been great. Small size yet feels durable.

Purchased to carry Gospel tract cards in for distribution, works beautifully !
Only one life will soon be past , only what's done for Christ will last !