Just when you thought windows could only be clad in metal. The Westeck Combo Window partners the natural richness of a wood interior with a fully extruded vinyl exterior. This new concept in window design delivers the best of both worlds. Combo™ windows are made up of a full vinyl exterior window with a full wood interior. As the interior wood of the window is behind the nailing flange, no moisture can penetrate the wood, causing it to peel, rot or the inevitable, having to replace the entire window.