50 Thank You Small Business Poly Mailers - Shipping Envelopes Northwest Ultra Suppliers 10x13 Inch Thank You for Supporting My Small Business Poly Mailers 50 Pack Durable - Waterproof, strong mailers with very strong peel-and-stick adhesive Size - 10"x13" Co-extruded LDPE Black inside to keep your packages secure Choose from 4 different colors or if you can't choose a color pick the multi-pack. You will receive 50 10x13" polymailers.