Maximum durability boxes are engineered specifically for active files, harsh environments, & professional records management applications where reliable file storage is critical. The automatic, instant set-up that doesn't require tape, allows you to get organized quicker. Built with triple panel construction all sides to ensure maximum durability & dependability. 3" deep detachable, lift-off lid. Box Type: Stackable File Storage; Box Style: Instant Assembly; Strength: Heavy-Duty; File Size Format: Letter / Legal.