We ordered a large acoustic grade Indow insert for a window that covered more than 60% of our front living room wall. The main reason we ordered the Indow was road noise. We live very close to a busy 2 lane road and were hopeful that the Indow would cut down on the road noise. Our installer explained that we should start with the biggest window for an insert. Our only other windows on this floor are a slider, a front door with a small window, and a glass door slider so we can't do any other Indow inserts on this level. Unfortunately, the Indow has not made that much of a difference. For the cost of the insert I would have hoped for a 50% or better sound reduction. When the road is dry there is more sound reduction (maybe 25%). When the road is wet I'd say the sound reduction is 10-15% vs without the insert. If I had to do it over I would not purchase the Indow simply due to cost vs effectiveness. I do understand that there are many purposes for the Indow aside from sound reduction, for instance the ability to keep certain windows in classic homes for insulation purposes.