Finished installing new Indow inserts about a month ago in our circa 1906 single pane, double hung windows. I was concermed about the outside rim making our already busy trim work look too thick, but it blends in fine and I barely notice it. We already see a noticeable difference in heat retention and noise abatement. Also, kudos to Indow team for excellent measurement instruction kit. It was very informative with clear instructions. More labor intensive but less guesswork than ordering mini blinds! 100% happy with our purchase and highly recommend, especially for older homes.