We ordered Indow inserts to reduce road noise to one of our rooms. The product does work as intended. We are happy with the quality of the product, however the measuring process is where we found the problem. We have window frames with some steps/ grooves. The task of measuring these special type of windows were left to the customer ( who doesn't have much experience in window measurements ). Due to this one of the inserts didn't fit the window properly, thus reducing the effectiveness of the insert. We felt that if these measurements were taken by an Indow dealer we wouldn't have the problem of non fitting insert.