Sure Petcare SureFlap Pet Door Mounting Adaptor, Used with Microchip and Connect for Cats Small Dogs, Install in Glass Doors Windows, Pack of 2, White

Amazon

Used to install the SureFlap Microchip Pet Door in windows or other glass panels Covers holes ranging from 294mm to 320mm in diameter Supplied in packs of two for the inside and outside of the installation Can be used to cover gaps left by previous pet doors The total diameter of the mounting adaptor is 380mm

ManoMano

The large mounting adapter for the SureFlap electronic chip cat flap allows for easy installation in glass, walls, and certain types of doors. It is suitable for small adult cats. This accessory enables mounting in holes ranging from 294 mm to 320 mm in diameter, with a total diameter of 380 mm.