Features: Made of high quality cardboard, the mailing box features a thick three-layer corrugated paper construction to provide better stability and firmness. Strong and yet lightweight, our mailing box will also ensure that your shipping charges are within reasonable limits. High quality cardboard E-Flute grade middle layer Strong and lightweight Crush-resistant structure Thickened three-layer corrugated board Die-cut folding Interlocking design 220x160x77mm