Pets are free in and out: The screen door is equipped with magnets at the bottom, closes automatically. Two sliding latches at the bottom of the flap help you lock the dog door, keeping your pets home when you're not home. Easy Installation: The dog door is easy to install. You can install it yourself. The cat flap package includes screws and an installation manual. Size: inner frame (21cm x 24.5cm) outer frame (25cmW*31.5cmH), select the appropriate height to install according to your dog's height. Suitable for most small and large dogs, cats or other pets, but not suitable for very small pets as the flap swings too heavy. Scope: The cat flap can only be installed on existing screen doors, hallways, windows or other screen windows. They cannot be used for very thick wooden and glass doors. If you have any questions during installation, please do not hesitate to contact us. Material: The screen door dog flap is made of ABS material, which is safe and non-toxic, harmless to your pets, smooth surface, wear-resistant, corrosion-resistant, easy to clean and has a long life expectancy.