The Automatic Chicken Coop Door comes ready-to-use. The door frame is 14.25" wide by 39" tall. Just attach the frame over a 10" wide x 13" tall opening in your chicken coop and plug it in to an extension cord. No assembly required. Plug & Play...without ever worrying about opening and closing the chicken coop door again. You will enjoy the freedom and your chickens will enjoy the protection of the Automatic Chicken Coop Door.