"For use in the installation of Pet Mate/Cat Mate cat flaps in walls. Comes with a 3 year guarantee, the Liner can line walls 5-10cms thick and can be used with multiple liners for thicker walls. It is also paintable. Any number of these 50mm (2"") sections may be added to cat flaps Ref. 234/235 to enable easy wall installation. Approximate size: 15.9 x 6.4 x 16.5cm."