Strong & Tear-Resistant Protection – Made from durable multi-layer polyethylene that resists punctures, tears, and moisture to keep your items secure during transit. Waterproof & Lightweight – Moisture-proof material keeps contents safe from rain or spills while reducing mailing weight and postage costs. Self-Sealing Convenience – Each poly mailer features a strong, tamper-evident self-seal adhesive strip for quick, secure, and frustration-free packing. Versatile 12x15.5" Size (#5 Medium) – Ideal for mailing apparel such as dresses, jeans, shirts, and hoodies, as well as books, toys, soft goods, and eCommerce orders. Perfect for Small Business Mailing – Professional white design provides a clean, polished look for online stores, boutiques, and small business packaging. These light weight poly mailers self seal for easy and secure packing. Each Large Plastic Poly Mailer is 12" x 15.5" in size. Our Poly Mailers are extremely durable and lightweight to help save you money on postage. Superior tear and puncture resistance. High strength seams for maximum protection. Silver lining inside keeps contents hidden from view. Surface easily accepts ink, stamps, and labels. Approved by shipping carriers. The lightweight poly mailing envelopes are perfect for sending small items via Fedex, UPS, USPS, or DHL. The self-sealing adhesive makes packaging your items for shipment fast, easy, and secure.