The customer service was excellent. Can’t say enough great things on that front. I ordered two windows as a trial before ordering inserts for all of the upstairs windows. One window was a perfect fit, the second was not snug in one corner. Both were measured the same way. Snug fit or not, the inserts did not reduce the noise (train horns) by a noticeable level. To be fair it is an older house so the noise may very well be from poor insulation and there is nothing any amount of window inserts can do. I also already have double pain newish windows. All in all I think it could be great for some use cases but if you are looking to damp down noise, and you have double pain windows, I would try one or two inserts first.