This Security Boss Custom Made Maxseal pet door is available for both walls and doors. This custom made pet door can be built to fit an existing rough cut, overall frame size, or unique pet opening size. The Maxseal pet door is the most energy efficient and secure pet door on the market. The UV treated and weatherized flaps will not crack, shrink, discolor or warp in any type of climate. The composite security panel expands and contracts in hot and cold climates and is the strongest security panel in the pet door industry.