The cascade card wallet is great and It's the one I use but overtime cards always start to fall. I added two 0.5mm tiles on the inner side that add extra friction for the card to not slip away and fall. It works good. You need to violently shake the wallet in order for the cards to fall while from the original wallet they could fall when you take it out of your pocket. Also I have removed the holes on the back because I found them ugly and now to unstick the inner mechanism you need to poke on the inside with a kitchen knife. It's pretty easy.