Found Indow on the internet while searching for noise reduction windows. Indow Customer satisfaction guaranteed. Indow stayed on top of things even the shipping of the measurement kit. Upon arrival, my contractor friend was surprised at how well the inserts were individually packaged and he could see the quality of the workmanship in each insert. He was impressed! And even more surprised by how easy to be installed. There are three HVAC units in one area. Our noise level now is "What noise I do not hear anything." Will need to invest the same for our kitchen windows. A great product few know about.