The Cat Door for Interior Doors is the perfect way to keep your cat safe and sound. With a larger opening than most 6″ x 7.2″ (with brush) or 7.5″ x 10.3″ (without) doors, this cat door is easy to install and provides a secure and comfortable home for your cat. The sleek design is durable and stylish, and the quiet operation won’t disturb you when you sleep or at work.