Purchased 2 units for our front bedrooms as we've been on a loud main road. Put in them yesterday and the difference in noise is astounding. I went for the 6.4mm laminated glass and positioned the models to the entrance of the window sill to give most gap. Tilt and https://edenl308iwj9.daneblogger.com/26574725/facts-about-thermal-insulation-secondary-glazing-revealed