This double-flap cat flap that is insulated is a great protection for all climates. It can be installed in wood, uPVC, glass, and steel doors. It is important to have a door that is sealed tightly, particularly during cold weather. It keeps warm air from being sucked out and cold https://catflapfitters02210.vblogetin.com/36397030/installing-a-cat-flap-in-a-upvc-door-cost