This extra SmartKey™ can be used for an additional pet using your Electronic SmartDoor™. Our innovative Smart Door™ recognizes the SmartKey™ worn on your pet’s collar and unlocks the pet door. After your pet has passed through and the SmartDoor™ no longer senses your pet's SmartKey™, it automatically locks back into place. Each SmartDoor™ can program up to 5 SmartKeys™.

The SmartKey™ is for use with the Small Electronic SmartDoor™ and the Large Electronic SmartDoor™ .

Also works with the Smart Pet Doorbell™