I bought these bedroom inserts primarily for sound reduction. My house is about a mile from a busy train track and several miles from an interstate highway with an exit close that has trucks braking. These inserts completely eliminated the interstate noise and the train rolling noise, and dropped the train whistle noise to very faint. No more waking up at night and counting trains. I measured carefully and the fit was perfect, and with the blinds open I can't even tell they are there. For info my jam depth allowed approximately 3" gap from the top window pane and 2-1/2" from the bottom and still allowed the use of an inside mounted 1" blind. Using the new compression blinds that install with no brackets allowed that much gap and maximizing the gap distance is important for sound reduction. I also installed jam stops specifically for the Indow insert to get it to the right place.