Metal binding makes it durable and easy to open and close
For binder notebooks, the weight will gradually increase, as the inner paper is inserted from the later.Therefore, if you do not have too many sheets, it is not a problem with thin and easy objects, but if you have a large number of sheets such as writing in a classroom or in a classroom, you may have a certain amount of tightness of binding tools that may break the binder.That is why this item is made with metal binding so it is very durable and will not break.