PlexiDor is known for offering a unique and attractive pet door. Their secret is using 2 dual-pane, hardened Acrylic flaps which swing open like a saloon door. Extra-large uses two single pane flaps, where the small uses a single dual pane flap. PlexiDor’s rigid flaps are far easier to seal then flexible vinyl. PlexiDor uses pile weather-stripping around the flap, in order to seal it to the frame. The doors are spring-loaded, and easily return to the closed position. Along with the advantages of a virtually unbreakable flap and good insulation, the PlexiDor is a great choice for climates that are severe. We are proud to offer the most aesthetically-appealing pet door available today. This unique door uses a keyed lock for daily use, and comes with a bolt-on steel cover in the Medium and Larger sizes. There is also an optional rail setup that allows the steel cover to slide into place, for daily use. The PlexiDor wall kit gives you everything that you need: the tunnel trip pieces, the flap assembly and the outside frame. Regardless of the color of the inner and outer frames, the tunnel sections are brushed aluminum..