Aviditi M642 Crush Proof Corrugated Mailer, 6" Length x 4" Width x 2" Height, Oyster White (Bundle of 50) Corrugated mailers are super strong yet light-weight to save on postage Perfect for shipping small, light-weight fragile items It is manufactured from 200#/ECT-32-B oyster white corrugated Crush resistant mailer folds to provide double walls of protection on front and sides Unique "Wave-Rule" edge virtually eliminates paper cuts