Big savings on shipping costs and cheap bubble mailers make these a great deal for a pack of 25 12.5"X19" #6 Our Poly bubble mailers are lightweight and durable, allowing for a great, safe, and cost efficient shipping method. The self-seal closure is tamper-evident and a secure way to close packaging. The bubble layer allows for overall protection of items within the package. This packaging method is also water-resistant and made of a multi-layer blend of polyethylene film.