Storage box features heavy-duty triple-end double-side double-bottom construction that stacks up stronger and withstands frequent handling. Use to store your letter-size and legal-size files. FastFold allows quick easy assembly. Reinforced tear-resistant hand holes make the box comfortable to carry. Deep locking liftoff lid stays in place for secure file storage. Smooth rolled edges add strength and prevent paper cuts. Stacking weight is 850 lb.