Heavy duty, triple-end, double-side construction stacks up stronger and withstands frequent handling. FastFold? quick and easy assembly. Reinforced tear-resistant hand holes make box comfortable to carry. Deep, locking lift-off lid stays in place for secure file storage. Smooth rolled edges add strength and prevent paper cuts. Stock up and save! Box Type: FastFold?; Material(s): 2 Ply Bottom; 2 Ply Side; 3 Ply End; Strength: Heavy-Duty; File Size Format: Letter/Legal.