*** Please allow up to three weeks for delivery *** If you have to be away from the house for an extended period of time, your dog can know have access to the yard when he wants. The Classic Medium Pet Door has a heavy-duty aluminum frame that withstands stress from even the most powerful breeds. A soft, transparent, single flap for maximum efficiency. Has an insulated, locking, rustproof closing cover has a locking pin and is the strongest and most secure available. Telescoping adjustable frame creates its own protective inner frame for doors 1/16″ to 2″ thick, may also be installed in walls. For pets up to 40 pounds. Flap size is 8″ x 11″