100-6x4x2 White Corrugated Shipping Mailer Packing Box Boxes Two 50 Bundles 100 - 6 x 4 x 2 White Corrugated Shipping Boxes Corrugated mailers are super strong yet lightweight to save on postage expenses. Perfect for shipping small, lightweight, fragile items. Each corrugated mailer is manufactured from 32ect-B oyster white corrugated.