100/200/500/1000 10×13 Self Seal Poly Mailers 2.5 mil thick.  Water, Tear and Puncture resistant The silver inner layer provides confidentiality High-efficiency mailers are perfect for shipping a wide variety of non-fragile items Pressure sensitive adhesive provides a high strength durable closure, water and dirt resistant UPS, USPS, and FEDEX approved100/200/500/1000 6×9 Self Seal Poly Mailers 2.5 mil thick. Water, Tear and Puncture resistant The silver inner layer provides confidentiality High-efficiency mailers are perfect for shipping a wide variety of non-fragile items Pressure sensitive adhesive provides a high strength durable closure, water and dirt resistant UPS, USPS, and FEDEX approved