Introducing our Paintable Cat Flap Wall Liner, a versatile and customisable solution that simplifies the process of installing the Microchip Cat Flap into walls. This innovative wall liner allows for easy and secure wall installations, making it an ideal addition to your pet-friendly home improvement projects. For a cavity wall, Cat Mate recommends using a total of 6 wall liners. This wall liner is compatible with the following products: Closer Pets Microchip Cat Flap (Ref. 7114429). Also requires Cat Mate Adapter Kit for Walls and Glass Panels (Ref. 7114430). If you are installing one of our products through a wall, or any section thicker than the Door/Flap itself allows, we recommend using wall liners to extend the product and create a tunnel. Each Liner section is 5cm (50mm / 2") and may be added to the following products to enable easy wall installation: Cat Mate Elite Microchip Cat Flap with Timer Control (Ref. 355), Cat Mate Elite I.D. Disc Cat Flap with Timer Control (Ref. 305), Closer Pets Microchip Cat Flap (Ref. CP360), Cat Mate Timer Control Cat Flap (Ref. 359), Cat Mate Rotary 4 Way Locking Cat Flap (Ref. 358W). Each Liner is 50mm / 5cm / 2" long, so if you need a 20cm tunnel, you'd need 4. They can be cut down, so for instance if you needed a 22cm tunnel, you can buy 5 and cut one down by 3cm. We advise that you can add a thin bead of sealant between each liner to create a moisture resistant tunnel, and a wrap around the outside of the joint with duct tape means the tunnel stays solid and is much easier to handle. You will also require a Cat Mate Adapter Kit for Walls and Glass Panels (Ref. 361) as this provide the Adapter between the Door/Flap and the tunnel, and also provides a neat faceplate for both inside and outside. Any number of these 50mm (2) sections may be added to any catflap in the Elite range to enable easy wall installation.