Double-end, 1 1/2-side, double-bottom construction. Medium-duty for use with or without shelving. FastFold® quick and easy assembly. Deep, locking lift-off lid stays in place for secure file storage. Rolled edges add strength and prevent paper cuts. STOR/FILE™ DIVIDERBOX™ —Five 5" dividers keep files upright even when the box is partially full. Box Type: Stackable File Storage; Box Style: FastFold® Quick & Easy Assembly; Strength: Medium-Duty; File Size Format: Letter.Package Includes: (60) Dividers, (12) Lids