Interlocking flap file storage boxes use unique overlapping flaps to lock into place and protect files from dust and other hazards.  Don't worry about losing or breaking lids again as these interlocking boxes are conveniently built from one piece of strong 200#/ECT-32 white corrugated material.  Featuring a double layered bottom for extra strength, you can be sure these easily assembled file storage boxes can stand up to rigorous file room usage.