For leak-free insulation, line your cardboard box with these plastic liners. These liners maintain the temperature of your shipment for up to 24 hours, making them ideal for shipments that would be damaged by heat, like perishables or electronics. Padded in bubble wrap, they protect your shipment without the bulk of paper liners or insulated foam. An adhesive strip for sealing prevents condensation or vapor from leaking outside the liner.