This is an Inside or Outside Mountable Locking Mailbox. Box was opened to Photograph and to insure that it included Keys and Mounting Supplies. There however, thereare no instructions inside. Little illustration on back ofbox only. Measurements are 12.6 X 8.6 X 3.4 inches. Opening Slot is 1 X 7 in. Also has a clear see through space at the bottom, so that you know when you have received Mail. Made of Galvanized Steel and Heavy Duty WeatherProof.and Rust Proof. Easy Installation, Pre-drilled holes. Please see Photos as they are a Part of the Description. Comes from a Smoke Free Home.