Works well for the back patio door so the dogs can go in and out without letting in all the bugs.  It does not come with instructions but luckily this is the third one I installed. Be prepared that it will not last for more than a season, especially if you have dogs.  I learned that the velcro strips that are provided will not keep it in place for long so I reinforced the top with black gorilla tape. It worked like a charm last year and kept it in place for the whole season.