You’ve heard of vinyl windows. You’ve heard of aluminum windows. But what you haven’t heard is that Marvin Essential™ fiberglass windows outperform them both. With Marvin Essential™ windows, you get the unmatched strength and low maintenance of Fiberglas both inside and out. The strength of the Fiberglass material lends itself to contemporary designs and narrow sightlines you won’t find in other materials. Factor in the special sizes and proven energy efficiency and you have a window that is perfect for any home.