Durable pet door made of sturdy ABS plastic with a thickened frame and security panel, allowing your pets to move freely while maintaining indoor security. Features: Durable ABS Construction: Made of thickened ABS plastic with a reinforced frame for durability and better sealing--keeps cool air in during summer and cold drafts out during winter. Flexible Silicone Flap: Soft and bendable flap design allows your pets to push through easily and securityly for free in-and-out access. attractive Closure Design: Built-in attractive strip ensures the flap closes automatically, preventing wind, rain, and drafts from entering. security Locking Panel: Features a sliding lock panel to control pet access, providing security and flexibility for both you and your pets. Specifications: Material: ABS Size (LxWxH): S: 29 x 4.2 x 35cm (approx.) L: 36.5 x 4.2 x 44cm (approx.) Recommended Size: S: For pets under 18kg, width below 8 inches, height below 9 inches L: For pets under 45kg, width below 11 inches, height below 13 inches Color: White Package Contents: 1 x Pet Door 1 x Installation Accessory Set 1 x Instruction Manual Please Note: Please make sure your pet is standing, measure the pet's chest circumference (width) and the height from the shoulder to the bottom of the chest (height), and choose the appropriate size based on the measurement results