The Electromagnetic Cat Door from Cat Mate protects your home from stray animals that might think it's a good place to explore. Using a small collar magnet, the door identifies pets you want to allow inside and instantly allows them to pass.
Door is self lining to 60mm (2 3/8"), and features an unbreakable flap and magnetic seals to keep weather and drafts out. Perfect for large cats and small dogs (up to 14"). 1 PP3/9V batter (not included) will yield approximately 12 months of operation. Carries a 3-year guarantee.