20″ x 24″ + 4″ Expandable Poly Mailers Case Quantity: 200 Highlights 4″ Gusseted bottom expands inside space Tamper evident, permanent self-seal closureTear and water resistant material 2.5 Mil thickness Our poly mailers are designed to protect your items during the shipping process. Made durable with a 2.5 mil thickness and tear resistant exterior, the bottom expands 4″ which allows you to package bulky items. Self-sealing adhesive strip makes these bags easy to close and gives your products added security. Great way to ship a wide variety of items.