SureFlap Microchip Pet Door Tunnel Extender-White-Large (for Pet Door)
The SureFlap Microchip Door Tunnel Extender allows you to mount the door into thick walls including a home's interiror and exterior walls.
The extender fits into the tunnel of the microchip door, and you can even use multiple extenders in extra thck walls - just stack them together to form a tunnel of any length.
Two sizes available:
Large Pet Door Extender - Adds 50mm to the existing pet door's 70mm tunnel.
Available in White
To calculate the number of tunnel extenders you will need, please refer to the chart below.