UCGOU Bubble Mailers 12×16 Inch 20-Pack Usable Size 12×15 Inch Large Padded Envelopes Teal Waterproof Packaging Bags for Shipping Self Seal Strong Adhesion Envelopes. The bubble mailers outer size is 12×16 inch, while the inner size is 12×15 inch. I purchased a 40-pack, but only needed 20. These are brand new.