Review on Premium RFID Blocking FRIFUN Card Holder for iPhone and Android Smartphones - Stick on Wallet with Slim Leather Design, Adhesive Cell Phone Wallet for Secure Credit Card Storage (Gray) by Thomas Unruh

Business card holder works quite well. My only complaint is that although I usually only keep about 3 cards in it, it's really, really difficult to get the cards out because the sleeve isn't flexible or stretchy at all. I would have to take them all to get the card I need. Other than that, this is a great product.