View the chart below to calculate the number of tunnel extenders you require to fit the depth of your wall.
SureFlap tunnel extenders can be used to create a longer approach tunnel to the SureFlap Microchip Cat Flap when it is installed in a wall.
The Cat Flap Tunnel Extender fits snugly onto the tunnel of the SureFlap Microchip Cat Flap and multiple extenders can be stacked together to form a tunnel of any length.