The mounting adapter is required if the Sure Flap Microchip pet flap is to be installed in glass windows, walls or metal doors, for example. It enables installation in openings with a diameter of 294 - 320 mm, the total diameter of the adapter is 380 mm. The mounting adapter ensures that everything is sealed airtight, preventing heat loss in the house. It is compatible with the Sue Flap Microchip pet flaps.