Made to let you install the SureFlap Microchip Cat Door, SureFlap Microchip Connet Cat Door and SureFlap DualScan Cat Door in glass doors, windows, or walls, this accessory allows easy mounting with no hassles or messy adhesives. It includes one part for the inside of your home and one part for the outside, and can be fixed directly to the wall, window or door using a circular hole with a diameter of up to 26cms. Designed to be mounted straight out of the box, it requires minimal assembly.