This insert was ordered for a window between 2 offices (all interior walls) due to the amount of noise. We had the wall filled with insullation, which made little-no improvement. Our next step was this window insert. Very quiet noise cannot be heard through the indow window now, but everything else is still very clear and loud, overall about a 20% improvement. We have a drop tile ceiling, which is likely the biggest problem, and not something we, as tennents, are able to change. The insert was easy to install, but 1 section of the instructions was VERY confusiong - the chain part, due to the size of the window. Online, the video's do not demonstrate inserts requiring the saftey chain, and the written instructions provide no description on how these are to be installed. Overall, I think the product is great, it just isn't as helpful as we were hoping for our space.