Extremely cheap window with virtually no energy efficiency whatsoever. These windows are popular with contractors because they have HUGE PROFIT MARGINS since they are made so cheaply. They claim energy star, but this is just for the glass which may be energy star, but the frame and plastic that holds the glass is extremely cheap and inefficient and has huge air leaks throughout the window tracks----AVOID. Note If you live in a climate that doesn't require any energy efficiency and your windows do not need to be air tight, these windows might be okay, however, these windows are priced in the same category as high quality windows. These windows are really only good for quick, cheap replacement jobs where you will not be living in the house and do not need the energy efficiency of a quality replacement window. Unless you like overpaying for cheap products there are plenty of quality alternatives to Simonton.