Etekcity 100#3 9x12&rdquo; Self-Sealing Non-Padded White Poly Mailers/Mailing Envelopes/Bags Pack of 100 9" x 12" 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!