Kraft corrugated mailers are light-weight to save on postage. Perfect for shipping small, light-weight fragile items. Manufactured from 200#/ECT-32-B Kraft corrugated. Crush resistant mailer folds to provide double walls of protection on front and sides. Unique ''Wave-Rule'' edge virtually eliminates paper cuts. These one piece mailers fold together in seconds. No tape, glue or staples needed. All ship and store flat to save space.