Freedom and comfort: A large cat door that allows cats or small dogs to enter and exit easily and quietly. They won't feel trapped, and you don't need to open or close the door for them. Safer with 4lock modes: By sliding the switches, you can adjust the access mode to In, Out, Full Locked, Out Only, In Only. This lets you control your pet's access and helps keep stray animals away. No tunnel part, no cutting required: The panels are only 2 cm thick and closefitting, suitable for windows, screen doors and sliding glass doors. Outer size is 19.7 x 19 cm, flap is 17 x 16 cm. Designed for cats and small dogs with a waist circumference shorter than 50 cm. Durable and comfortable: Made of robust ABS plastic, with a longlasting inner door. Sealing strips and a magnet for alignment help keep bugs and the smell of cat litter out, while reducing cold air loss in summer and heat loss in winter.