The company states that BLOCKIT Sleeves will protect your privacy and secure your most valuable data from digital pickpocketing. Each BLOCKIT Sleeve is engineered using 3 performance layers - A layer of aluminum material blocks 13.56MHz frequencies, a copper substrate layer blocks all 125kHz, while the outer layer is a glossy paper with attractive full color design.
These are great to have to protect your information. With so much credit card theft that happens these are a good thing to keep in your wallet or purse. I received this product complimentary in exchange for my unbiased opinion and review.