Universal® Deluxe Quick Set-up String-and-Button Boxes are ideal for storing heavy files and keeping documents organized. The sturdy, corrugated construction adds strength and value. Equipped with a string-and-button tie closure, you can securely store box contents and not worry about them tipping over and spilling out. Box Type: Stackable File Storage; Box Style: Easy Assembly; Strength: Medium-Duty; File Size Format: Letter.