Fits Large Sized Pets: MIAOTONG Dog door replacement flap measures 10 1/8 inches (W) x 16 7/8 inches (L), the insulation pack measures 10 1/16 inches (W) x 16 7/16 inches (L), and there are 5 holes at the top of the flap. Package includes 2 flaps and a heat pack, and screws Heat and Cold Resistant: MIAOTONG Doggie door replacement flaps feature a double-flap design with built-in insulation to withstand all types of inclement weather, with temperatures ranging from -20°F to 120°F. Ideal for use in extreme climates Flexible and Durable: MIAOTONG Doggy door replacement flap is fitted with a magnetic strip at the bottom to ensure that the flap closes safely and securely when the pet passes through, preventing mosquitoes from entering Easy Installation: MIAOTONG Pet door replacement flap installation process is simple and quick, no complicated tools are needed, just a common screwdriver with our included screws can complete the installation Note: Before ordering a dog door flap, please make sure you check the location and size of the screw holes on your home's dog door to ensure that the optional flap will perfectly match your existing dog door Designed to withstand a wide range of weather conditions, the MIAOTONG Dog door replacement flaps not only provide extra protection against inclement weather, but also help keep your home at a comfortable temperature. Magnetic strips ensure a secure closure every time against outside weather and pesky insects. Easy to install with the included screws, the MIAOTONG dog door flaps are a convenient solution for pet owners looking to upgrade their existing pet door and are a must-have for any pet-friendly home.