OEM Quality Park Survivor First Class Envelopes, packaged with 100 envelopes per box. These open-end catalog envelopes feature a patented release strip for easy opening and a convenient Flap-Stik closure that eliminates the need for moisture to seal. Made from DuPont Tyvek, they are designed to be stronger and more secure than traditional paper envelopes, resisting rips, tears, and punctures. Additionally, these water-resistant and moisture-resistant envelopes are lightweight, helping to save on postage costs.