I had someone who know this neighbor contractor, so I hired him to taking measurement quoted me with very good price $4500, than when brought window for 12 of them, and install them, as install them, he says made mistake on calculation, so add another $ 2000 so I paid, now every window is so call thermo protect by argon gas, all them are leaking moisture inside (between) 2 pane glasses, these windows are used some poorly mixture of the seal are expanded and cracked up the frame of the window, now I am looking for another set window, this company sale contract so terrible too, not trust for next time, less than 7 years old window. need replacement again.