https://zenwriting.net/quietdr....op5/cat-flap-double-
This double-flap cat flap that is insulated provides excellent protection in all climates. It is available in wood, uPVC, glass, and metal doors. A tightly sealed door is essential, especially in cold weather. It stops warm air from being sucked away and cold air from entering, saving money on energy costs. Wind Resistance By preventing cold air from entering your home and keeping warm air in the cat flap, it keeps it warm. The best ones come with magnet seals and are protected by insulation. They are also equipped with a lock t