Pet Door Tunnel Extender SureFlap pet door tunnel extenders can be used to create a longer approach tunnel to the SureFlap Microchip Pet Door when it is installed in a wall. The Pet Door Tunnel Extender fits snugly onto the tunnel of the SureFlapMicrochip Pet Door and multiple extenders can be stacked together toform a tunnel of any length. The tunnel of the SureFlap Microchip Pet Door is 70mm (2.75") long and each tunnel extender adds 50mm (2") to the length of the pet door’s tunnel.View the chart below to calculate the number of tunnel extenders yourequire to fit the depth of your wall.
