Selective Entry/Exit: Securely attaches to your pet's collar, ensuring only your pets can access the SmartDoor, keeping unwanted animals outside Custom Schedules: Use the My PetSafe app to customise each pet's access schedule, providing tailored permissions for the SmartDoor Connected Pet Door Size Compatibility: Available in small, medium, and large sizes, ensuring a secure fit for your pet. The small key is compatible with the medium SmartDoor, while the medium and large sized keys are compatible with medium and large doors Easy Attachment: Comes with a split ring for simple and secure attachment to your pet's collar, ensuring the key lays flat for optimal performance A 27 Year Legacy of Joy: Since 1998, PetSafe has been dedicated to creating innovative products that ensure safe and healthy pets, bringing happiness to pet families worldwide and enriching the lives of pets and their owners