Polar Tech's 'Nestable' combo is offered as a completed set, with the foam container inserted in each shipping box. We take the guess work out of trying to find the correct shipping box by supplying them together, fully assembled. Our foam and box combo is typically taped on the bottom and only requires the end user to load the box with appropriate refrigerants, product, tape, and ship. Our superior quality offers durability, temperature control, and the box adds additional preprinted handling instructions, such as Rush Perishable and This End Up for carriers and recipients. Foam is nestable within each other when box is purchased separately. These products are MTO (Made to Order).