This type of file box is the standard for vertically/flat organizing and storing Letter and Legal-size files. The one-piece hinged lid design provides a safe, acid and lignin-free container that can be used for long-term storage and protection. Folders Our file boxes are also suitable for storing and removing thin books, brochures, and magazines. Folder divider If you need to place the files upright when the folder is not full, you can purchase it separately. The spacer is adjustable and can be used for letter and legal-size document boxes.