Light-duty storage boxes offer a sturdy corrugated construction for strength and value. String-and-button closure secures box contents. Storage boxes are ideal for storing and transporting letter-size files. Average amount of evenly distributed weight that can be safely stacked on top of each box is 350 lb. Each file box contains a high percentage of recycled material.Business Source Light Duty Letter Size Storage Box White 12 / Carton (Quantity)