The PetSafe Ultimate Pet Door has a heavy duty aluminum frame designed to stand up to the most extream conditions and dog sizes. The PetSafe Ultimate Pet Door Works Perfectly. Wouldn't it be great if your dog could open doors? It could go in and out when it pleases and you haven't locked the flap. If you are away from the house for any length of time, your dog now has access to the yard through your new PetSafe pet door. When your dog travels outside,the PetSafe dog door flap opens out then falls back in place, the second PetSafe dog door flap creates a tight magnetic seal around the door frame. When your dog comes back in, the two flaps seal together to work as one dog door flap. A closing locking panel is included so you can keep our dog inside and undesired animals out. The PetSafe pet door by is easy to install, Simply cut a hole using the template provided in the instruscions and screw the two durable frames together. Now your dog can come and go as he pleases. Freedom and convenience for you, and for your dog.