12 x 12 x 12" 500#/ECT-71 Heavy-Duty Double Wall Boxes. Twice the protection of a standard carton. Boxes are manufactured from Heavy-duty 500# D.W./ECT-71 kraft corrugated. Heavy-duty construction provides greater protection and stacking strength. UPS rates these cartons up to 140# capacity. Corrugated boxes are reusable and recyclable. Cartons are sold in bundle quantities and ship flat to save on storage space and shipping. Proudly made in the USA