The NT – Executive Series Window is an all-purpose single hung window designed to maximize energy efficiency and durability. We at Adams Exteriors are big fans of the North Texas Windows line and when we can we prefer to buy from well established local manufacturers like NT. This is a “standard” window designed to compete well in a southern market where heat infiltration is usually the biggest concern. The Executive Series window is 100% vinyl (except for the hardware, glass and metal reinforced meeting rail) and includes 7/8″ Cardinal 366 Glass. Like most quality replacement windows, the frame measures 3-1/4″ wide and is multi-cavity for greater efficiency.