📬 Mail with Confidence: The Ultimate Survivor Envelope! White Tyvek with a professional finish Pack of 100 for all your mailing needs Flap-Stik closure for secure sealing Patented release strip for easy access Puncture, tear, moisture, and chemical resistance Moisture-resistant 10x13 size Puncture-resistant The Quality Park R1590 Survivor Tyvek USPS First Class Mailer is a robust, 10 x 13-inch envelope designed for secure and reliable mailing. With its patented release strip, this pack of 100 envelopes offers effortless opening and a self-seal closure, ensuring your contents are protected against punctures, tears, moisture, and chemicals.