USPS/UPS/DHL/FedEx Approved Poly mailers are ... 100 % RECYCLABLE Superior tear and puncture resistance. The silver inner layer provides confidentiality. Pressure sensitive adhesive provides a high strength durable closure, water and dirt resistant. High-efficiency mailers are perfect for shipping a wide variety of non-fragile items. Water, Tear and Puncture resistant. Lightweight saves on postage. High strength seams allow for over-stuffing. Have a question about this item?