Quality Park Tyvek Expansion 10in x 13in x 1 1/2in Envelopes, 18 Lb, Self-Adhesive Closure, White, Carton Of 100

Ideal for securing bulky mailings Expanding gusset helps get your extra-thick mailings through the mail. Redi-Strip closure requires no moisture to seal. Made of water-resistant Tyvek material.