🐱【PET DOOR SIZE 】 XSmall Size: Outer Size: 7.4" x 7.8" x 1" ( W x H X D); Inner size: 5.7" x 6" ( W x H) ; Cut-Out Size: 6.3" x 6.7" (W x H); Fit Cats up to 16 lbs，Suitable for any wall or door that is up to 50mm thick; Small size: outer size: 7.5 x 7.8 x 2 inches (W x H x D); inner size: 6.1 x 6.3 inches (W x H); cut-out size: 6.3 x 6.7 inches (W x H); fits cats up to 16 lbs, suitable for any wall or door up to 50 mm thick. Medium Size: Outer Size 9.25" x 9.92" x 2.16"(W x H X D), Inner size:7.08" x 7.48"(W x H), Cut-Out Size: 7.7" x 8.3" (W x H), suitable for installation on doors and thin walls, suitable for cat lighter than 17.64 lb and waist circumference shorter than 23.62" Large size: outer size: 9.8" x 11" x 2.15" (W x H); inner size: 7.9" x 8.7" (W x H); cut-out size: 8.3" x 9.5" (W x H); fits cats up to 27.54 lb, suitable for any wall or door that is up to 50 mm thick. 🐱【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 out 🐱【 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. screws and its caps included in the set make you easily install in doors, cupboards, panels and walls, etc 🐱【 SAFE &THOUGHTFUL】The cat door 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. Exterior screen is for waterproof. Brush strip reduces noise from the door closing. The cat flap door with magnet that let the flap can be quickly reset when the cat passes.