Using the mounting adaptor for wall installations enables you to installthe cat door more easily because you can use it to fix the cat door to thewall without the need for messy adhesives. The mounting adaptor is notrequired to install the Microchip Cat Door Connect in a wall as thisproduct contains wall mounting screw holes within the front frame. The CatDoor Mounting Adaptor includes two parts, one for the exterior and one forthe interior of your home.Using the mounting adaptor for wall installations enables you to installthe pet door more easily because you can use it to fix the pet door to thewall without the need for messy adhesives. The mounting adaptor is notrequired to install the Microchip Pet Door Connect in a wall as thisproduct contains wall mounting screw holes within the front frame. The PetDoor Mounting Adaptor includes two parts, one for the exterior and one forthe interior of your home.