for walls are models that have included or as an option; a tunnel that lines the pet opening through your wall thickness. These models are the most commonly used by customers with cats. They tend to have features that are specific for cat usage such as the common
4-Way Locking feature. This setting allows you to manually set the door so that once you cat enters the house, they cannot leave again. This feature is common on many electronic cat door models when used in the manual mode only.