Security: The In-n-out Pet Door dog door offers the best security on the market. Why? Because the dead bolt lock works as normal and there is no big hole for a burglar, raccoon or snake to crawl through. It works as a dog door on glass and a dog door on French doors. It works as a dog door for small to giant dogs and is an easy to install and remove dog door, 9 screws and you are done, no cutting, measuring or special orders. The dog door attaches to the door, no big hole required. Got big and small dogs try stacked paddles for your dogs in and out needs. The dog door comes with easy to follow installation instructions, hints on how to introduce your dog to the in-n-out pet door, parts list, tool list, and installation diagram. There are also videos at in-n-outpetdoor.com.