Bought 2 units for our front bedrooms as we've been on a noisy primary road. Set up them yesterday and the difference in noise is wonderful. I went with the 6.4mm laminated glass and positioned the units within the front with the window sill to give most hole. Superb customer https://davidg432vka0.popup-blog.com/26562257/5-tips-about-noise-reduction-windows-in-chelsea-you-can-use-today