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This cat flap is insulated and features a double-flap design and offers a good level of protection for different climates. It can be installed in wood, uPVC, glass, and metal doors. It is important to have a door that seals tightly, especially during colder weather. It keeps warm air from being sucked away and cold air from getting in, saving money on energy costs. Wind Resistance Covering your cat's flap for winter will help to keep your home warmer