1.4 There are four closing options for each closing type cat valve: inward opening, outward opening, two-way opening and closing. If your pet wants to enter the room, you don't need to open the door again. Catdoor makes your life easier and your pet more free at home2. Easy to install. It is suitable for brick walls, wooden doors, PVC and metal doors. This pet door can be installed on doors and walls with a thickness of 2.5 cm.3. Shirt door size - frame size: 19.7 * 19cm (W x H), door size: 16 x 15.7cm (W Height), thickness: 5.4cm.4. Very quiet: This free wheel door is very quiet and provides the best ventilation protection through special sealing and magnetic closing. The brush strip eliminates the noise when opening and closing the door. Suitable for most cats and dogs (Pomeranian, Yorkshire Terrier, Pekingese, Dachshund, etc.).5. The transparent flap is made of high-strength glass fiber, which has good ultraviolet resistance, transparency, anti pet grasp and bite, moisture resistance and wear resistance.