Thermo Seal also offers the Endure line of vinyl windows. This type of window is extremely energy efficient and has been independently tested to meet strict energy efficiency standards and is ENERGY STAR® certified. Endure Windows are available in a wide array of styles including Double Hung, Horizontal Slider, Picture, Casement, Awning, Bay, Bow and more. All of these windows are available in many color options including Bronze Laminate exteriors with a lifetime warranty and interior woodgrains to name a few.