The PetSafe® Pet Door allows you to control your pet’s access. When set to automatic mode, only your pets wearing the Electronic Pet Door Key can pass through the Pet Door. As your pet enters the range of the door, the Electronic Pet Door detects the key and unlocks automatically. The range is adjustable up to 3 feet. After your pet passes through the Pet Door, it will lock automatically helping to keep the house pets in and outdoor animals out. Trust PetSafe® to help keep your pet healthy, safe and happy.