SureFlap Microchip Pet Door Tunnel Extender-Brown-Small (for Cat 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:
Small Cat Door Extender (for both the Dualscan and Standard microchip doors) - Adds 50mm to the existing cat door's 70mm tunnel.

Available in Brown

To calculate the number of tunnel extenders you will need, please refer to the chart below.