The OEM Quality Park Open-End Envelope is designed for secure and convenient mailing. Featuring a patented release strip, these envelopes are easy to open and utilize a Flap-Stik closure that does not require moisture to seal. Made from DuPont Tyvek, they are significantly stronger and more secure than traditional paper envelopes, resisting rips, tears, and punctures. These water-resistant and moisture-resistant envelopes are lightweight, helping to save on postage costs.