500 12x16 WHITE POLY MAILERS ENVELOPES BAGS 12 x 16 ValueMailers is a Registered Trademark. High Quality Self Sealing Mailers! Water, Tear and Puncture resistant. The silver inner layer provides confidentiality Pressure sensitive adhesive provides a high strength durable closure, water and dirt resistant High-efficiency mailers are perfect for shipping a wide variety of non-fragile items.