Patio Pacific Pet Doors has made it their focus to design and build the very best pet door flap. The most important feature in a pet door is the flap. The flap of a pet door can have many problems such as they don't insulate, they pinch the pet, they blow open, or they don't fit the pet and they wear out quickly. Patio Pacific Pet Doors have developed the best flap for pet doors called endura. Patio Pacific Pet Doors can boost they have the best, most highly engineered pet door flap ever made. Patio Pacific Pet Doors come in either a single flap or double flap. if you need a pet door that is extremely tough and durable to conquer the most extreme situations then Patio Pacific Pet Doors is made just for you.