These 9.3" x 12.3" x 10" Corrugated Boxes have a thin corrugated wall designed for stacking strength. Box strength is measured using the Edge Crush Test (ECT); the corrugation used in these boxes can withstand 32 pounds per square inch (32 ECT). (Box contents should not exceed 35 lbs.) Boxes meet ASTM-D5118. Cartons are sold in bundle quantities and ship flat to save on storage space and shipping.