•   The PetSafe 4-Way Cat Flap, White (originally the Staywell 300 4-Way Locking Cat Flap)
   
•  The PetSafe Cat Flap Magnetic 4-Way, White (originally the Staywell 400 Magnetic Cat Flap) or
   
•   The Staywell 500 Infra-Red Electronic Cat Flap

to make them "self-framing" in a wall of any thickness.

Each tunnel section is 1 7/8" wide. Purchase enough tunnel sections to reach the full thickness of the wall. Each of these cat flaps is already self-framing for installation in a door so these tunnel sections are only required for a wall installation.

The Staywell 940 Tunnel Section is designed for use with the Staywell 919 4-way Locking Cat Flap. Each tunnel section is 7/8" wide. Use the 919 and 940 tunnel sections for a wall mount of any thickness.

You could add a Staywell 940 Tunnel Section to a Staywell 919 to make it self-framing for a door. However, a better choice is to purchase the Staywell 917 which is self-framing from 0"-2" and adequate for nearly all doors so that no additional tunnel section would be required.

These tunnel sections may be used with the Staywell 917 as well. Keep in mind that the Staywell 917 already provides up to 2" of self-framing distance in a wall mount so 1 less tunnel section would be needed.

Staywell 310
Tunnel Extensions
(one tunnel section
per box)

Staywell 940 Tunnel Extension for 919 Cat Flap (one tunnel section
per box)