기능

• The back width changes according to the amount of documents, so you can always store documents in a compact way.
• Even if there are only a few documents, the back width is not bulky and there is no wasted space. Can be stored compactly from the beginning of use.
• Even if a large amount of documents are put in, the documents are stored neatly without being rolled up. Since the file does not swell, the cover can be closed tightly.