9.5" x 12.5" Quality white large rigid shipping envelopes mailer with pouches, tear strip tab and self-adhesive seal.  Stay Flat Envelopes: Protect letters, documents, photos and other valuable when mailing with quality cardboard flat shipping envelopes. Our rigid mailer is not only durable and made with reliable quality that provides bending resistance, it also features a slit open pouch insert for print out labels. Simple to use use self-Adhesive seal that keeps your valuables secured in the stay flat mailers while in transit and easy to open with a tear strip tab for conveniency. Measures at 9.5 x 12.5 inches, perfect for all sized document, media, letters and more. Approved for USPS, FedEx, UPS, and DHL Extremely durable and lightweight cardboard material helps save on postage 50 stay flat shipping envelopes per pack.