Bought 2 models for our entrance bedrooms as we've been on a noisy major highway. Installed them yesterday and the main difference in noise is astounding. I went to the six.4mm laminated glass and positioned the units around the front of your window sill to give highest gap. We're a https://gardenpathwaylights25814.blogars.com/26431917/the-retrofit-double-glazing-in-london-sw3-diaries