This TRIXIE 4-way cat flap door with 2 tunnel elements gives your pet a free pass to enter or leave the house even when the door is shut. Cats often change their minds several times a day about where they want to be. Hence, you may not feel like opening the door for your pet all the time. This is why the cat flap door is a perfect choice. This cat flap door has a transparent flap and works silently. The cat flap door can be set in 4 modes: open both ways, closed both ways, only open for getting out, only open for getting in. The 360° circumferential seal and turn-lock fastener help to keep out the breeze. The 2 tunnel elements are included for walls and thick doors. You can also buy more tunnel elements to extend the cat flap door.