Mailing bags safe for travel up and down conveyor belts during transit measure 5 x10 #00 - Pack of 250. Self-sealing mailers are easy for businesses to pack and ship lightweight items. Reduce postage and bulkiness when smaller items. Our Poly bubble mailers are lightweight and durable allowing for a great safe and cost efficient 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.