DUAL-FLAP EXTREME WEATHER DESIGN: our double-flap insulated pet door offers maximum energy efficiency, protecting your home from harsh weather conditions, and keeping it cool in the summer and warm in the winter; the flexible flaps remain functional even in temperatures as low as -40°F; small flap measures 6" x 10" and is suitable for pets up to 14" tall INSULATED FOR ENERGY SAVINGS: this energy-efficient pet door features dual-pane LoE glass that reduces UV rays and infrared light, helping to conserve energy in your home; the dual-flap system creates an effective barrier against drafts, ensuring optimal indoor temperature control SECURE LOCKING MECHANISM: designed with safety in mind, featuring a secure locking cover, as strong as 1/16" steel, that prevents unauthorized entry when not in use; enjoy peace of mind, knowing your home is protected while still providing your pet with easy access to the outdoors SEAMLESS INTEGRATION WITH VINYL SLIDING DOORS: pet door is specifically engineered for vinyl-framed sliding glass doors with 'U' shaped tracks (minimum 1-1/2" thick), ensuring a perfect fit and seamless integration with your existing door for optimal insulation and energy efficiency BUILT & BACKED FOR LIFE: the Endura Flap pet door is designed with flexible, heavy-duty flaps that swing on a rod at the top to prevent cracking and flexing, ensuring long-lasting durability even with continuous use; backed by the Endura Flap lifetime guarantee The Endura Flap Vinyl Panel Pet Door presents a superior solution for pet owners seeking an energy-efficient and durable option for their vinyl-framed sliding glass doors. This product stands out for its exceptional insulating properties, making it a top choice for those living in extreme climates. Crafted from high-quality vinyl, this pet door is specifically designed to integrate seamlessly with vinyl sliding glass doors. The vinyl frame not only fits comfortably in the door track but also complements the aesthetic of your existing door setup. This feature is particularly beneficial for maintaining the original look and feel of your home. One of the key highlights of the Endura Flap Vinyl Panel is its insulated dual-flap system. These flaps offer enhanced insulation, maintaining their flexibility in temperatures ranging from -40°F to 110°F. The energy efficiency of this pet door is further boosted by its dual-pane, Low-E glass, which minimizes both UV rays and infrared light, helping to maintain comfortable indoor temperatures and reduce energy costs. Designed for versatility, the Endura Flap Vinyl Panel accommodates various sizes of vinyl sliding glass doors with 1.5" thick 'U' shaped tracks. This makes it suitable for a wide range of door configurations. The product offers various size options to cater to pets of all sizes, from small cats to extra-large dogs. For added security, the pet door includes a secure locking cover and a c-clamp lock. These features allow you to control access and ensure safety when needed. The pet door's spring-loaded design facilitates easy, semi-permanent installation, ideal for rentals and vacation homes as it requires no permanent alterations to your property. The flap is lined with magnets on all sides, capable of staying shut in winds up to 50 mph, providing additional protection against the elements. Adjustment range fits slider heights between 74.75" - 77.75".