1.Classical Double-Switch 4-Way Locking Design: Easily move the red/green switches, the cat door shows 4 modes to lock: Free Access, In Only, Out Only and Totally Locked. Quite sufficient and convenient. The magnet on the bottom will make it back to the original place after cats pass through the cat door. Another thing to note is that if the rotating shaft is stuck by the cold weather, only need to drop a few drop of oil (without freezing) on it, you will find it returns smoothly 2.Upgraded Weather-resistant Brush: A slot with buckle is provided to fix a soft weather-resistant brush. The brush will cover the gap of the flame, effectively reduce the noise outside and prevent the rain, wind, snow, mosquito and other insects from entering. I n winter, the installation of cat flap will defend cold and keep warm. The design of brush will make it possible for you to rest in silence when cats passing through the cat door, especially at night. Enjoy Nights silence 3.Easy to Install:The cat doors for interior doors have detailed installation steps, this large cat door can be installed easily in a short time. 8 screws and its caps included in the set make you easily install in doors, cupboards, panels and walls, etc 4.SafeThoughful : The cat door with lock have transparent cat flap that cat can see through. The pet doors for cats have silent brush that can reduce the noise from the door closing. 4 way locking of the big cat door meets cats daily need. The cat flap door with magnet that let the flap can be quickly reset when the cat passes. Inner frame edge of the cat interior door get polished, so as not to hurt cat 5.XL Size: Outer Size: 11 x 9.8( W x H); Inner size: 8.7 x7.8 ( W x H).Make sure that the cats weight should be lower than 17.64lbs and waist less than 23.62in. The cat flap can be installed on interior doors, exterior doors, walls, cupboards and glass, etc. Once completed the cat door will greatly facilitate your life after installation, saving you time to open the door, and freely control the cats entry and exit