Ultra Hardware, 67105, 3" x 10", Polished Brass US3, Mail box Letter Slot, Double Flap, Use In A Door or Wall, Double flap: outside and inside, Fully hinged Spring loaded single flap opening, Outside And Inside: 3" x 10" outside with flap, Inside opening: 1-5/8" x 7-3/4" Polished brass finish, Openings conform to postal regulations, For use with wood and metal doors, Furnished with matching inside trim plate and screws.