Quality Park Survivor Tyvek First Class Envelopes - First Class Mail - 3 1by2 - 10 W x 13 L- 14 lb - Peel & Seal - Description: Patented release strip makes these open-end catalog envelopes easy to open. Convenient Flap-Stik closure does not require moisture to seal. First-class envelopes made of DuPont Tyvek won t rip tear or puncture. They are much stronger and more secure than traditional paper envelopes. Water-resistant and moisture-resistant envelopes are lightweight to save on postage costs. Envelopes are easy to use. Simply peel and seal. Features: Product Dimensions: 10 W x 13 L Weight: 14 lb Peel & Seal. Tyvek Color: White Country of origin: US Brand Name: SURVIVOR Model No: 2088-QUAR1590