The DuPont Survivor Tyvek Envelopes are a durable and reliable option for shipping and mailing needs. These 9×12” envelopes are made of Tyvek material, ensuring they are strong and tear-resistant. Perfect for businesses looking to send out a large quantity of mail, these envelopes are designed for first class mail with a sturdy construction that can withstand handling and transit. With the trusted DuPont brand, these envelopes provide peace of mind for your shipping requirements.