Ordered two inserts, one fits okay, the other has a gap. I will mitigate the gap when I get the chance by altering/shimming the window frame. From standing near the insert that fits, the results are really unsatisfactory. I was simply trying to prevent my rude neighbor’s dog from waking me up in the early morning. That goal was not achieved; not even close. I still clearly hear birds, people talking and love volume, slow moving passenger cars and dogs in my bedroom. The sound is dampened, slightly, but I was hoping to really attenuate the high frequencies. I understand that treble bounces and bass permeates. Understood I wasn’t going to defeat the sound of say a garbage truck or helicopter, but the performance for the cost just isn’t there. These were a waste of money. If effective, I would have done multiple rooms. The salesman knew my objective: dog vs. Indowondow. Was told these inserts were the solution. They were not. Just glad I only dipped a toe and didn’t order for all bedrooms.