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.