I’m am very happy with my inserts. They were purchased to reduce outside traffic noise in our master bedroom. We live on a busy road but have beautiful large windows. They have reduced the noise from our double pane windows by at least 50 % and on some days/times even more. I can still hear some car noise outside which I fully expected but the inserts have reduced it to a much more comfortable amount, to where it’s just a very low sound. We have so many windows in our master bedroom & bathroom we could not do all of them at once. We didn’t do the bathroom or attached office yet, just near our bed area which is 5 large windows. I am planning to buy more in the future. I feel based on what we have done so far it would only make it even better. I was so worried about spending the money but I feel it has been worth it!