These days, many people use container boxes as storage and space.

However, container boxes are weak in heat, cold, and moisture due to the nature of the material made.
So there are many inconveniences to live with only ordinary windows.​

The folding door has a large insulation, soundproofing, and windproof effect compared to the general window, so it can make up for the shortcomings of the container box.

The hot temperature in summer is transferred to the container box, so the inside is no different from the steamer, and the folding door can be opened and closed to quickly remove the heat from the container box.

It can also proceed quickly with heat and ventilation.