[Chocaholic]

They make a cheaper version with one flap also. Had that one at our old house. Worked fine for years but went for the heavy duty version (forgot what it’s called) when we moved. I think I payed about $600. Two thick flaps that do a great job of keeping cold/hot air out, double pane glass, etc. Took the pups a few days to get used to the heavier flaps but now they go through like nothing.

We have a mutt with diabetes insipidus. Drinks copious amounts of water and pees all the time. The dog door saves us from getting up to let him out twice each night and we’re able to be gone more than a few hours at a time. Life saver.