Direct Mail Economy size, 6 1/2" x 9 1/2", Double-Sided, Full Color Mailers on .007 inch thick cardstock. Same or next business day service! Shipped Priority Mail® Medium Flat Rate Box (with 2-3 day expected delivery). We can ship up to 800 mailers in each Flat Rate Box. You will be prompted to upload your file upon completion of checkout. 6-1/2" x 9-1/2" no bleeds.