1.4 WAY LOCKING : The cat door with lock have 4 switch modes, the pet doors for cats could be adjusted by the red and green switches with tabs, can be set to open, in only, out only or fully locked, easily adjustable making it easy to keep your pets in or out2. 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. 3. SAFE&THOUGHTFUL : 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 cat’s 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 cat4. SIZE : The large cat door is made of ABS material, weather-resistant, the surface is smooth and durable. The inner size of cat door with lock is 7.09″” (W) x 7.48″”(H). It’s suitable for Weight < 17.64 lb Waist Circumference < 23.62"" The outer size of pet doors for cats is 9.25"" (W) x 9.84"" (H) x 2.09"" (D)"