Survivor® 9 x 12 First Class border catalog mailer made of 14 lb. DuPont™ Tyvek® with Redi-Strip® closure. Our Survivor brand mailers are made from DuPont™ Tyvek® protective material which is strong and durable to easily withstand the most grueling conditions. The material is virtually indestructible because it isn't paper ... it's Tyvek®! It is puncture, tear and moisture resistant and when you're sending something important, that's exactly what you want your envelope to be. Every day, mailers provide a highly effective and useful way to send important information and items to others, whether from home or from work. With the exceptional durability and unique image of Tyvek, along with the wide variety of styles and sizes available, Tyvek First Class border mailers can help increase the effectiveness of your important mailings and the assurance that the contents and your message will be delivered. They feature a Redi-Strip® closure which requires no moisture for a secure seal and a release strip for quick, easy opening. They are also light weight which could save on shipping costs. No matter what your job entails, DuPont™ Tyvek® mailers can help you be more efficient and effective with your correspondence and delivery of important items. Tyvek® is a trademark of DuPont used under license by TOPS Products LLC.