STOR/FILE Exrta Strength Storage Box Letter/Legal White/Blue 12/Ctn - String and button closure keeps contents secure even if box is overturned. - FastFold® quick and easy assembly. - Medium-duty stacking strength for use with or without shelving. - This product was made from wood sourced from a certified managed forest. - Box Type: Storage Material(s): 1 Ply Side 2 Ply Bottom 2 Ply End Strength: Medium-Duty File Size Format: Letter/Legal.