Originally empty, it was vulnerable to noise, and cold air or heat from outside came in at once, and heating costs and electricity bills were high.

It was a great addition to separating the interior more refined and saving fuel costs. In addition, it is constructed with a type that opens on both sides, and is installed with a clean white frame.

In particular, the inside of the other side is bright, so the design of the folding door is more revived and it has been changed into a clean interior.

Folding doors are also used for separating the interior from the outside, but are also used in many ways to make the space between the interiors more solid.