I back onto a busy road, so I was looking for a solution to reduce the noise. After much research, I bought one Indow insert to see if it makes a big difference and planed to get them for the entire house if the test went well. I had no issues with the fit...actually fit like a glove. The result...it does reduce the noise somewhat especially tire/road noise. Does pretty much nothing for engine/exhaust noise. Now why just one star? I have two issues. First, with the insert installed, it creates air pressure which causes the insert to push out which was super annoying having to push them back into position everyday. Second and a HUGE issue for me is that I have Vinyl windows facing west and it got so hot that these inserts baked and melted my window frames. After a summer, my windows were so warped that I couldn't get my screen out and needed to replace my window. My house is brand new (2 year old) with brand new windows so old windows are not the blame. I regret my purchase because not only did I lose the $1500 for the insert, I am also out the cost to replace my brand new window. Bottom line is that if you have vinyl windows, don't buy these inserts.