Purchased two models for our front bedrooms as we have been on a loud major road. Set up them yesterday and the difference in noise is incredible. I went for that six.4mm laminated glass and positioned the models within the front of your window sill to present most gap. https://englandp887ldu7.madmouseblog.com/15148292/helping-the-others-realize-the-advantages-of-soundproof-windows