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.