Item M-3 are bubble mailer envelopes that measure 8-3/8" x 13-1/4". This item is great for packaging and shipping your goods safe and sound. The padded mailers work great for wrapping your products which make it very safe to ship your products through a variety of shipping services. These mailers combine the moisture resistance of a polyethylene bag with the cushioning of 3/16" x bubble lining. The white padded mailers are tear resistant adding greater protection for your products.