Made of ABS plastic, durable, scratch-resistant for your cat/small dog. Also, easy to clean and can use for a long time 4 locking modes: open, closed, single entry or single exit, which allows your cat to come and go as they please without you losing control of their comings and goings This Magnetic Pet Door is suitable for Windows, glass doors, brick walls, PVC, uPVC and metal doors With this cat flap you can control your pet's comings and goings and free your time to open the door without worrying about your pet. At the same time your pet will like a big and free house Prevent unwanted animals from entering your home How to install To find a door and draw a square according to the size of the flap To drill 4 holes in the four corners with an electric saw 3To cut the square, and insert the cat flap into the hole (If the tunnel is thicker than your door, you can cut it according to your needs) To screw the cat flap with a screwdriver.