The PetSafe Freedom Patio Panel Pet Door allows your dog or cat to come and go as it pleases through your sliding glass door. These doors feature a heavy-duty aluminum construction and shatter-resistant, tempered safety glass. It's also equipped with the energy-conserving ultraseal flexible flap system designed to keep the heat and cold outdoors.. Heavy-duty aluminum frame with tempered glass - fits left or right sliding glass doors up to 81 in. Tall. Weather resistant - durable aluminum frame including weather stripping and slide-in closing panel for weather resistance.