a little flimsy, not as sturdy as another brand

They completely block radio signals from the RFID chip embedded in the credit card. I slid my transit pass RFID card in one and, when I pressed it to the reader pad, the reader noticed nothing.

Nowhere in the listing did it say that credit cards must be together in a stack with a blocker card front and another on the back of the pile. My credit cards are each in individual slots in my wallet so these are useless for me. Additionally - they are flimsy. Just paper. I can't imagine they will last very long.

Products I have tested in order of thickness from THICK to thin:(they are all same size in width and height dimensions)DATALOCKhttps://smile.amazon.com/gp/product/B019A804GM(my top choice)Shield Cardhttps://smile.amazon.com/gp/product/B00R1IE5BY(best value)D-Armorhttps://smile.amazon.com/gp/product/B00CJHZLEW(my second choice)Credit Guardhttps://smile.amazon.com/gp/product/B019DC2JQS- this itemTesting method used:RFID test - android phone with NFC capability with App called "Credit Card Reader"put the target card and RFID protection cards in different slots of my walletto test the strength of protection for each of the card tested.(my wallet is a trifold. test will work with bi-fold as well. I just simplytried putting the protection card and target card close together and thentried putting them far apart. I have also even tried taking them bothout of the wallet and putting phone directly on top of the cards.Once that was done, in eash scenerio, I put my phone with app runningdirectly over where I wanted to scan and tested to see if it would readand how far I had to be from the card to be able to read it.)Water test - to see if they are waterproof and if they can handle beingsoaked in water for long time. Avoid "Credit Guard". It failed big time.all others passed.Tear test - to see how easy it would be to destroy the product and see if they canlast long time. Same. Avoid "Credit Guard". all others passed.Test results and things I have discovered:-In case of DataLOCK, size did matter. It had 50% better protection than all of the others.for all rest of them, size did not matter and were equal in their strength of protection.-D-armor, Datalock, ShieldCard all were water proof. Sadly, for Credit Guard, not only wasit flimsy, and soaked in water easily in less than 3 minutes. It also easily torelike paper with no protection what so ever.-DataLOCK and Shield Card are on the thicker side, but only DataLOCK actually had benefitsof its thickness. Shield Card was 2 times as thick as other cards but providedno additonal protection so it will add much bulk to your wallet without actually providingextra security.-An interesting thing I have discovered is that, the protection cards do NOT have to be betweenthe target card and your scanning device. Just by being in close proxmsimity,RFID protection cards were able to block reading of the target card. This appliesto all of the cards.-If you do plan on having alot of cards in your wallet and you expectyour RFID protection card will have too many cards to protect or you plan to positionthe 2 far from eachother, I then do recommend using 2 protection cards by placing one on eachside of the wallet to keep the credit cards in the middle.My tip:- I really love DATALOCK. It has the best protection overall. But it only comes with 1.while some come in pack of 2 and some even more with passport protector providing great value.I would be willing to fork up extra money to buy 2nd DATALOCK, but because its bulky thicknessI have a much better idea that will still take use of its great protection.I will keep DATALOCK on one side of the wallet facing toward potential thief whileD-armor (my second favorite choice and thinest) on the other side of the wallet (while closed ofcourse)to protect the other end facing my butt. So that no matter wether I have my wallet in my pocketor I have it out in my had ready to cards out, it will always be protected.And because you are now protecting both side of your wallet with 2 cards, you will never haveto worry about how many credit cards you have in your wallet. Thickness of your walletwon't matter anymore and you will have the best protection.

I saw these on Shark Tank and after having my identity stolen once I decided, "what the heck"! So I've been using this in my wallet for a while now and though I can not prove if it works or not, I certainly feel more secure and so far have not had anymore incidents. So I'm giving it 5 stars!

Did you watch that Shark Tank episode talking about why you need to block your cards? I did! And then I got really paranoid about my credit card numbers being stolen. I was able to get these cards at a discounted price for my unbiased review. I'm so happy I was able to receive them, their lightweight and don't interfere with the thickness of my wallet. I don't have to worry about slipping them in and out of an envelope either. Big plus, I even got to share a set with my spouse so we're both covered. I can't wait to recommend these to all my friends.

The product arrived quickly and was as presented - 4 cards to slip into your wallet & you're off. The cards are easy to use, fit easily into card slots - even in my snug wallet.I have no way of knowing how well (or if) they work to prevent RFID theft but it gives me a little piece of mind.

I've always been concerned about credit card security so when I heard about this sort of product I was interested in protecting myself. These are so simple, and with four of them I can protect my own wallet, my wife's purse, and have extra in case we lose any. The quality of these cards seems very good, I have a coworker who also purchased a similar item but the quality of these is much better.I will recommend this product to my family and friends.