Size: 4 1/8" x 9 1/2"Bottom Window Size: 4 1/2" x 1 1/8" Bottom Window From Left Side: 4" Bottom Window From Top: 1 3/8"Material: White WoveSeal: Moisture Seal
These lines of text will inform the United States Postal Service of additional requests in the case that the mail is undeliverable. When these services are used, there is an additional fee to the USPS, information on the fees can be found here.