100 Poly Mailers Shipping Envelopes Self Seal Packaging Bags | 2.0 Mil Poly Mailers are a type of shipping envelope made from a durable, puncture-resistant material called polyethylene. They are commonly used for shipping items such as clothing, books, and small electronics. They are lightweight, waterproof, and tamper-evident, providing a secure and cost-effective way to ship items. They come in a variety of sizes and thicknesses, and can be custom printed with a company’s logo or branding. They also have a self-sealing adhesive strip that allows for easy and secure sealing of the package. Size: 14.5″ x 18.5″ + 2.5″ Flap self sealing