Indoor Pet Door: This pet door can be attached to the door to help pets get in and out smoothly. Typical pet doors require installation and construction, but this product can be easily installed by simply attaching and installing them. Even medium-sized dogs and large dogs cant pass through the flap doors can be smoothly transferred and traveled. Easy to install: The door is a "open door". Not for use on sliding or folding doors. Attach the two fixing rings to the wall or door frame at 1m intervals, and the other one to the door and attach the silicone rope. Please note that the more you adjust the rope, the more you need to open the rope. For an estimate, the width of the pets body should be 0.8-11.8 inches (2-30 cm). (Also suitable for heating and cooling preventions) The door automatically closes after your pet comes out, so it can also be used to prevent air conditioning and heating wind from flowing out during the summer and winter. You can adjust the speed of door closing by adjusting the rope wrap. This pet door is suitable for all types of pets, such as cats, dogs, small dogs, medium dogs, large dogs, old dogs, and more. [Product Details] Door body: 9.8 x 5.5 inches (25 x 14 cm); Silicone rope 666.6 ft (200 m); About returns: We will provide 30 days of returns from the date of purchase. In that case, please contact Amazon Customer Service. The color of the actual product may differ from the images depending on your monitor and photography environment.