Unlike pet flaps that require you to cut a hole in your door, this patio door insert provides unrestricted passage for your pet yet attaches securely with just a screwdriver. Made of sturdy aluminum with tempered safety glass, the insert secures to your door jamb with no sawing or drilling. Once the insert is in place, your sliding glass door opens and closes normally. A security lock installs easily to prevent the door from being opened from the outside; the pet opening may be locked from the inside. A weatherstrip and rubber bumper ensure a tight, yet flexible seal between your fixed and sliding door, and the insert can be removed easily for off-season storage. Adjusts from 77 5/8" to 80 3/8" high to fit all standard patio door openings. Minimal assembly. White. Large. Pet opening: 15" H x 10 1/2" W. Door insert: 15" W x 3/4" D x 80 1/2" H. (20 lbs.)