Bought 2 units for our entrance bedrooms as we're on a noisy principal highway. Installed them yesterday and the main difference in noise is remarkable. I went with the six.4mm laminated glass and positioned the models on the front in the window sill to give highest gap. No position is https://superman00876.mybuzzblog.com/6355747/not-known-factual-statements-about-noise-reduction-windows-in-chelsea