- Our 500-count #10 double window envelopes (4-1/8 in x 9-1/2 in) are designed to perfectly accommodate select QuickBooks invoices and statements, ensuring that your important documents are presented professionally. - Featuring Redi-Seal press-to-seal flaps, these self-sealing envelopes eliminate the need for moisture. Simply raise the lower flap and press down for a secure seal, making mailing as easy as possible. - With a double window design, these envelopes display only the sender and receiver addresses, protecting sensitive information from prying eyes. The top window measures 1" x 3-1/2" and the bottom window measures 1-1/8" x 4", adding an extra layer of privacy to your mailings. - Our security envelopes incorporate a special pattern that obscures identification numbers and private data, ensuring that your envelope contents remain confidential even when viewed under light. Practical applications include: - Sending out invoices or statements directly from QuickBooks while maintaining a professional appearance. - Mailing sensitive documents such as account statements or tax information without fear of exposing private information. - Using these envelopes for personal correspondence that you want to keep discreet and private. These envelopes not only provide functionality but also enhance the security of your communications, making them an essential choice for any business or individual concerned with privacy and professionalism.