I think that the item description is only the overall size of the product and the effective inner dimension is about 297 × 218 × 15 mm. (I am sorry if it was overlooked) I am considering repurchasing. I think that it is good that fasteners are devised and opened from both sides.
Purchased for storing documents of different sizes together on a bookshelf. I think that it is convenient for saving documents that are difficult to bind to files. Although I used it for about 1 year, the price was also cheap and it was not deformed or damaged, so I bought it again.