Made for frequent and heavy use by pets, the Hakuna Pets Super Tough Pet Door is built to last. Suitable for pets up to 9kg, the flap opening measures 170mm wide x 240mm tall. This pet door is suitable for interior and exterior doors, walls, screens and glass up to 55mm thick. Control your pets access and secure your home with the built-in Locking Clips. Ideal for most cats, Chihuahuas, Papillons, Yorkies, Pomeranians, Maltese, French Bulldogs and other small breeds.