The PetSafe® SmartDoor allows you to control your pet’s access. When set to automatic mode, only your pets wearing the SmartKey™ can pass through the SmartDoor. As your pet enters the range of the SmartDoor, the SmartDoor detects the SmartKey™ and unlocks automatically. The range is adjustable up to 91 centimeters. After your pet passes through the SmartDoor, the door will lock automatically helping to keep the house pets in and outdoor animals out. Your pet deserves the best. Installing your pet door is a simple DIY project and can be installed into any standard-size panelled, wood, metal or PVC door that is 32mm to 51mm thick. Key Benefits:The SmartDoor features programmable selective entry, exit and auto-locking optionsGreat for multiple pet householdsProgram up to 5 SmartKeys™ to the doorInstall into standard size panelled, wood, metal or PVC doors or walls 3.8 / 5 cm thickBattery-operated door uses 4 D-cell batteries, * not includedIncluded:SmartKey™ uses 1 PetSafe® RFA-67 battery Wall Conversion kit- SJ0385