The cat fly is made of high-quality ABS material, durable and easy to clean, perfect for indoor/outdoor doors, windows, cabinets and other wooden doors. Easy to Install: There is a detailed installation guide in the cat door to help you install it quickly. Contains 8 long screws and 8 short screws, please choose the appropriate screw according to the thickness of the door. The thickness of the cat door can be cut according to the thickness of the door. 4 Switch Modes: The pet flap can be set with 4 mode switches: only out, only in, free in and out, fully locked, easy to control pets in and out. Product Details: The sealing brush strip of the pet cat door can reduce the noise when the pet door is closed. The cat door seals well to keep pests like rain, wind or mosquitos from entering your home. Dimensions: Internal dimensions with flap opening: 18 x 18.5 cm, External frame dimensions: 23.5 x 27.5 cm, maximum thickness 5 cm. Suitable for small dogs or cats so they can come and go freely.