Give your pets the ultimate freedom and security with the Electronic SmartDoor™. This innovative automatic dog door uses radio-frequency technology to detect a SmartKey™ worn on your pet’s collar. When your dog approaches, the battery-powered flap unlocks—allowing them to come and go safely. Once your pet passes through, the flap automatically locks again to keep your home secure from strays and unwanted animals. Key Features SmartKey™ Technology: Each SmartKey™ transmits a unique signal that unlocks the door for your pet only. Multi-Pet Compatible: Program up to 5 SmartKeys™—perfect for multi-dog or cat households. 3 Access Modes: Automatic Mode – flap unlocks only for programmed SmartKeys™ Locked Mode – keeps the door fully secured, no entry or exit Unlocked Mode – free entry and exit for all pets Battery Powered: Runs on 4 D-cell batteries (not included). Secure & Convenient: Keeps stray animals out while giving your pets controlled access. Durable Design: White frame blends easily with most home interiors. Size Options Small – For Dogs Up to 15 lbs ($149.95) Outer Frame: 9" W x 15 ⅝" H Flap Opening: 5 ½" W x 7 ⅞" H Cut-Out Size: 8 ⅜" W x 14 ¾" H Large – For Dogs Up to 100 lbs ($204.99) Fits Door Thickness: 1 ½" to 2" Outer Frame: 16 ⅛" W x 23 ⅝" H Flap Opening: 11" W x 16" H Cut-Out Size: 15 ⅝" W x 23 ¼" H Each Electronic Dog Door comes with one SmartKey™. Additional SmartKeys™ are sold separately for multiple pets.