Review on MEKU Wallet: Genuine Leather Business Minimalist Men's Accessories – The Perfect Blend of Style and Functionality by Kevin Campos

I bought the six card slot version (no clear window). It's fairly thin as advertised and easily holds six cards, tight enough that they won't fall out but loose enough that they can be easily removed. The middle pocket can also hold cash or cards (although of course the more cards/bills you add the slimmer the wallet gets). It doesn't open automatically when you squeeze the sides as it seems in the pictures. It's not as handy for instant access as external slots, but works great if you want to carry some cash or an extra card or two for emergencies.