This PetSafe magnetic cat flap Deluxe 420 will give your cat a free pass to enter or leave the house even when the door is shut and helps to keep stray cats outside. Put the included magnetic collar key on your cat, which will unlock the cat flap for your cat! This PetSafe pet flap was formerly known as the Staywell pet flap. It is suitable for cats of up to 7 kg. The Staywell magnetic cat flap has a 4-way security lock (locked, open, in-only and out-only) and a weather-resistant flap closure for greater control of cat\'s access to your home. This energy-efficient cat door is easy to install with its universal fitting for windows, walls and doors of up to 5 cm thick. When the door is more than 5 cm thick, you can add more tunnel extensions.