This little Tyvek sleeve seems rather frail but it does a huge job: protecting your passport or credit card numbers from being lifted by remote sensing devices available to anyone with $100 and some time on their hands to sit in an airport. Considering the possible mess that such a theft would create, this inexpensive sleeve (they come in various sizes and quantities) is a good buy--and the customer service person was friendly, helpful, and part of the company's home office staff.