Sliding patio doors can mean easy in and out for your pet This beautifully designed, high-quality patio pet door inserts into the frame of your sliding glass door and automatically adjusts to the proper height. The panel can be installed in the left or right door, and it has an UltraSeal energy-conserving flexible flap system to reduce energy loss. Panels are available in Bronze and White in 4 sizes for sliding doors up to 81 high and in White in 3 sizes for sliding doors up to 96 high.