Door or wall too deep for your pet door? Add a single or multiple extensions for your pet's ease! This tunnel is compatible with the Staywell® Classic Manual 4-Way Locking Cat Flap (919 Series) and measures 18 mm (3/4") deep.
Not compatible with the 900 Series Staywell® Classic Magnetic 4-Way Locking Cat Flap.
WARNING:
Small children can pass through door.