16 diffrent sizes, please purchase according to the size of the inner frame and outer frame of the door frame,please refer to the picture of the size tabel Attached and removed in a few minutes, very quick and easy to install without tools and without drilling Quick and easy to install in minutes with the included Velcro strips and pins; no permanent damage to your door frame from drilling or nailing. Magnetic locking system allows easy hands-free entry and exit. Children and pets can also easily pass through the net. The strong net keeps insects outside and lets in fresh air, cats and dogs, the polyester fly screen is of the best quality and very durable. Two small sticky velcro tapes are designed on the left and right sides, so you can roll up the curtain at any time.