What is the best dog door or cat door for a wall? The PlexiDor is the best pet door for a wall. This durable pet door is crafted from the finest materials to withstand time and weather. It is available with a white, bronze, or brushed aluminum frame. The wall kit comes with an aluminum tunnel to cover the inside of the wall, and the tunnel should be installed with a slope to lead rain and snow away from the wall. The PlexiDor dog doors range from small to extra large, and there is a cat door. The panels open easily enough for a smaller pet to share the door with a larger pet. The PlexiDor is a construction-grade pet door with a good weather seal that keeps weather outside, helping keep heating and cooling costs in check. The saloon style panels are made from K9-composite – a material similar to airplane windshields – that will maintain its integrity down to -50F (-46 C). The PlexiDor dogdoors and cat door come with a 10 year warranty.