Therma-Tru. Using technology once reserved for more expensive lines, the Fiber-Classic Mahogany Collection replicates the grain of mahogany hardwood in a fiberglass door. Simple lines, architectural details, and a range of door-glass options make Fiber-Classic Mahogany ideal for Craftsman, bungalow, Arts & Crafts, and mission-style architecture. Composite top and bottom rails offer increased rot resistance while LVL stiles improve structural integrity. The Energy Star–qualified doors offer insulation and durability, and may qualify for federal tax credits up to $1,500. 800.537.8827.