Inserts for windows can make a huge difference. People get better results when they use lots of them.
Different Inserts Will Fit Inside Multiple Windows in Different Parts of the House
Some people will just want inserts for a few of their windows, while other people will want to add them to most of their windows. These windows might vary in size, and it will still be possible to position an insert in all of these different windows, including the windows that are built into doors.