i got the $20 janky piece of crap. i used the tension rod at the too and velcro-stickies on the sides. the center snaps together with magnets. it does protect me against bugs! it is totally worthless for keeping cats in, and may be worse because there’s a false sense of security: we must be ever vigilant about the cats.
it’s okay for now. vis-a-vis cats i treat it as if
it doesn’t exist, so i sit in the doorway and make the cats leave if they get close. but it does keep bugs from getting in.
i bought and returned a “screen door protector” that would have been utterly useless for us.
closing for now because we don’t think we’ll pursue the expandable-retractable screen door at this time.