The poly mailer bags are with durable and self-sealing, convenient packaging, with anti-open, super safe seal. Pressure-sensitive adhesives provide high strength, durable seals, water resistant and stain resistant, made with multilayered polyethylene sheets, provide an excellent waterproof & cushioning protection for shipment. Rain or shine, they provide the ultimate protection for your mail, work great instead of paper versions to protect products. Mailers uses opaque, high-quality materials to protect your privacy and has a professional look.