No. 9 Double Window Security Envelopes for Invoices

These No. 9 flip and seal double window security envelopes are ideal for sending invoices and business statements. They feature a self-seal flap that allows for quick and secure sealing by flipping and pressing. The envelopes measure 3 7/8 inches by 8 7/8 inches and have two windows for easy address visibility. Designed for convenience, they eliminate the need for moistening or additional sealing methods. The double window layout ensures that recipient information is clearly displayed, reducing the chance of misdelivery. Made from durable paper, these envelopes provide a professional appearance and reliable security for sensitive documents. They are suitable for various business mailing needs, offering a straightforward and efficient way to send important correspondence.