All the other reviews have commented on how effective these windows are, so I will not say too much –they really work. What I want to say here is how efficient and professional Richard and his team are. From the get-go, Richard provided honest information, with accurate an quote. We were told that these windows are not cheap, but if you want a quiet room to live and sleep in, it will be more than worth the money. After we paid for the windows, they arrived after 5 weeks. Richard and his team were there, waiting for the delivery truck, and they did all the unpacking, delivering, and installation. They were courteous and professional. Everything is done in a couple of hours. Then you are left with a super-quiet room, standing there wondering “Why didn’t I do this two years ago?”