I bought two of these replacement windows from a local business recently . I had heard that the Certainteed brand was an excellent one after doing some research and asking around. Also, the contractor had been in business for quite a few years and had an excellent reputation . I felt confident going with this brand to replace the 50 plus year old windows in my house . I chose to replace only two initially to see if I was happy with them before replacing the entire house's windows and I am glad that I did . The old windows were drafty as you might expect and I was told I would see a world of difference with the new ones - unfortunately , that was not the case . The new windows were even more drafty than the really old ones . I called the contractor back and they did come after a few weeks . Unfortunately, the day they came was bright and sunny so it was hard to show him what I called " air leaks ".The previous week had record low temps so that was when I needed them to come . These windows are draft and cheaply made , in my opinion, I will not rush to replace the others which are made better and have stood the test of time .