Many vinyl windows look very similar from the outside. It's typically what you don't see that makes a big difference. Strassburger uses the PH Tech Boreal line, which is well known in the window industry as one of the most durable and sturdy extrusions. This excellent reputation is due to an exclusive uPVC formula which gives the systems better resistance to impact creating a product durable enough for severe weather conditions. Another benefit of the Boreal extrusion is a combination of chamber wall thicknesses and the high number of chambers in each component. This construction lends itself to superior performance.