Extra long 1.5 inch Self-seal flap for easy closure and guarantees a secure seal every time. Tough, Tear-Proof Polyolefin Self-Sealing Envelopes Mailer Lightweight, saves on postage. High strength seams allow over-stuffing Ink, stamps, and labels adhere easily Water resistant Tamper resistant PE-LD/HD 3 layers, 50 - 90 micron, 2 colors (top frost) 40 micron PET film with full-face silicone coating 60 gsm and Breadth 10mm Hot Melt adhesive on flap Note: Lower 48 U.S. Shipping only. No P.O. box or AFO/FPO box addresses please.