High quality material. The outer frame is made of durable polypropylene, which is weather resistant and easy to clean. Long lasting, UV resistance, high transparency, can prevent animal attacks and bites, resistant moisture and wear. Easy to install. This cat door is suitable for brick walls, metal doors, wooden doors and PVC doors. Can be installed on doors and walls 2.5 cm thick. Low Noise: This pet door is very quiet. Easy to use and very gentle. It is very dense and prevents the flow of air, which makes it very suitable for winter. Simple and high quality design. The transparent cover allows animals to see through the door. The outer screen is waterproof, you can clearly see the movements of cats or dogs. Convenient and practical, this is a great solution that allows your cat to enter any indoor space while being fully controlled. Keep the door closed to keep a distance between dogs, cats and even at the right time.