Doggy Doors longevity is directly proportional to the speed of the dog using the door. Try to locate it in a convenient access point, but not a full speed straight shot.

Can't recall what brand that we have any longer. Steel frame on each side with an opaque plastic type flapper in the middle. The bottom of the flapper has magnets that keep it closed. Also has a flat sheet of steel that slides into place & locks it shut. Every once in a while the flapper needs to be removed & re-centered.

Good luck
~JM~

I certainly can't. I hit my head on them every time!