Purchased two models for our entrance bedrooms as we're on a noisy main street. Set up them yesterday and the difference in noise is wonderful. I went with the six.4mm laminated glass and positioned the units over the front of your window sill to provide most gap. The secondary glazing https://charless764wit6.blognody.com/26492152/5-tips-about-noise-reduction-windows-in-chelsea-you-can-use-today