These super heavy-duty packing boxes are manufactured from 350# doublewall corrugated. Optional partition kit includes: 3 sets of partitions and 2 layer pads (sold separately PARTKIT).Cartons are printed with fragile warning and this side up arrows and feature a convenient write on destination panel for deliver to instructions.Boxes feature hinged hand holes that makes them easier to carry.5.2 cubic foot capacity.Sold and shipped flat in bundle quantities.