Expandable mailer made with DuPont Tyvek material delivers the best possible protection at a shipping-cost-saving weight. Inserting and removing contents is easy because of its horizontal, open side orientation. Self-adhesive Redi-Strip closure provides a secure, peel-and-press seal. Clean, crisp look makes a professional impression. Lightweight – 14 lb. Seam Type: Center; Flap Type: Square; Trade Size: #15; Security Tinted: No.