Mailing Bags safe for travel up and down conveyor belts during transit measure 9.5"X14.5" #4 - Pack of 100. Self-sealing mailers are easy for businesses to pack and ship lightweight items. Reduce postage and bulkiness when shipping smaller items. 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.