Extreme Weather Protection: The PetSafe Extreme Weather Aluminum Pet Door has a triple-flap thermal barrier that blocks 3x more energy than standard doors, helping maintain the indoor temperature Durable Aluminum Design: Heavy-duty exterior frame with reinforced corners ensures long-lasting, multi-pet access for cats and dogs; the large size is for big dogs up to 100 lb Easy DIY Installation: Fits most exterior doors made of wood, panelling, PVC or metal sized 1.5-2" thick; includes slide-in locking panel for secure flap closure and controlled pet access Global Mission, Local Care: With U.S. roots and worldwide reach, PetSafe delivers vet- and trainer-recommended solutions and exceptional customer support to create fields of joy for pets 25 Years of Trust: Since 1998, PetSafe has created safe, innovative, and trusted products that bring joy, enhance pet lives, and support the lifelong bond between pets and their families