Etekcity 500 pcs Premium PM2 7.5&rdquo; x 10.5&rdquo;7.5x10.5 Self-Sealing White Poly Mailers/Mailing Shipping Envelopes/Bags Pack of 500 7.5" x 10.5" poly mailing envelopes with water, tear and puncture resistant High-efficiency mailers are perfect for shipping a wide variety of non-fragile items The silver inner layer provides confidentiality Pressure sensitive adhesive provides a high strength durable closure, water and dirt resistant Thick poly material, durable yet with lightweight, saved you a bunch on shipping cost!