Makes lives easier, gives dogs more independence: Give your dogs an separate access, they can going out or coming in every time they want and you no need to get up every 5 minutes to open the door for them. Automatic close and lockable: 2 magnets on the door frame, the pet door will close quickly after your dog passes by, and because of the magnetic force, flies and other small insects can't get in. 2 blue locks allow you to lock the door completely and cannot be passed through. Super easy to install: Install the door frame on your screen door with the small nuts, then cut the screen and install the door flap, installation complete! Please note the position of the installation, it is recommended the highest point of the dog door is about 2” higher than the dog's back. Small dog door size: Inside size: 10”*8”*0.5”, outer frame size: 11.5”*9.5”*0.5”. Suitable for cats and small dog puppy, please measure the size of your pet and compare to the door size before purchasing. How to teach your dog: Your pet may afraid to use this door at first, you just need to give them time to get used to the door. You can put dog’s favorite food or toy on the each side and guide dog through once and once again, they will learn to use it soon.