Excellent design and performance

An excellent design. So far I have measured the “flap” inside temperature to be about the same as a modern double glazed vinyl window 4 feet away. The airflow from the unit is not perceptible. Our dog likes it, however our cat is still unsure. The only thing I could think of to make it better would be to offer a translucent flap that would be double wall with a center hollow for a little thermal barrier.. but I also recognize that would be much more subject to wear.