Quality Park Survivor Expansion Mailers are built to protect what matters, whether you’re shipping important documents or storing vital records. Made from durable DuPont Tyvek, these 10\" x 13\" envelopes expand up to 2 inches, giving you flexible space for bulky contents without added weight or cost.\n\nUnlike heavy paper envelopes or boxes, Tyvek envelopes are puncture-, tear-, and moisture-resistant while remaining lightweight (about half the weight of traditional paper mailers). That means reliable protection and lower postage costs with every shipment. These tough expandable envelopes stand up to overstuffing, rough handling, and bad weather, helping ensure your delivery arrives intact. The material is virtually indestructible because it isn't paper, it's Tyvek!\n\nEach mailer features Quality Park’s Redi-Strip self seal closure for fast, secure sealing. Just peel and press, no moisture required. The adhesive is protected by a removable paper strip, keeping it sticky even after storage. Self sealing envelopes also support cleaner mailroom workflows by reducing contact with envelope surfaces.\n\nThese versatile mailers easily accommodate books, manuscripts, transcripts, clothing, and thick stacks of paper. The opaque white Tyvek material protects privacy. With 25 mailers per box, Quality Park Survivor Expansion Mailers are a convenient, cost-effective solution for shipping, mailing, or waterproof storage of essential documents. Tyvek is a trademark of DuPont used under license by TOPS Products LLC. (Manufacturer Item Number: QUAR4202)