Acquired 2 units for our entrance bedrooms as we have been on a loud main highway. Set up them yesterday and the main difference in noise is awesome. I went with the 6.4mm laminated glass and positioned the models about the front of the window sill to offer utmost gap. https://damientgnaq.webdesign96.com/27307646/not-known-factual-statements-about-noise-reduction-windows-in-chelsea