| Wing 
                and V-tail are produced in a sandwich construction with rohacell 
                as supporting material. To improve the everyday practicality 
                of the lightweight construction the outer layer of the wing is 
                made of 50g glass or IM-spread-tow-carbon. 
 
 | Erwin 
                XL medium is also built in sandwich-construction. The 
                outer skin is made of 70g IM-spread-tow-carbon for the 
                wing and 39g-carbon for the V-tail. The upper sides are painted, the undersides are 
                left in visible carbon using spread-tow fabric.
 
 | Erwin 
                  XL slope is manufactured in a special building method 
                  without sandwich. The outer skin is made of robust 160g 
                  carbon. Because of that, the surface of wing and V-tail 
                  is extremely durable.Upper sides are painted, undersides left in visible 
                  carbon.
 
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