We, always be there to get the door for your best friend, no matter the weather. The PetSafe Extreme Weather Sliding Glass Pet Door is our most energy-efficient pet door option for sliding glass doors. The dual-paned glass, weather stripping and 3 flexible flaps with a magnetic seal help keep the hot or cold weather out and the air conditioning or heat in for increased energy-efficiency. Available in 2 sizes, this door is a great option if you live in an apartment or rental home because it can be easily installed without cutting or drilling into your sliding glass door frame. The pet door arrives in 2 sections with a top and bottom panel. Simply attach the panels together and insert the pet door into your sliding glass door track. The pet door has a spring-loaded height adjustor to ensure it properly fits in place. Secure the pet door using either the included removeable adhesive strips or screws. To lock your sliding glass door, place the security bar between your door frame and the interior sliding portion of your glass door. Simply unhook the security bar from the bracket to unlock your sliding glass door. When your pet isn using the door, slide the closing panel over the pet door opening and lock it in place for extra security and energy efficiency. Soon your dog or cat will be able to freely explore the great outdoors with their own personal pet door! Trust PetSafe to keep your pet healthy, safe and happy.