Shaft: Double horizontal birch lamination covers a two-piece aspen core, reinforced by vertical fiberglass lamination. Unique ultra-light design. Highly refined assembly techniques ensure constant weight and stiffness. injected polyurethane foam with continuous fiber strand mat for shock absorption. Covered in fiberglass and carbon fibers for optimum durability and stiffness. blade reinforced with fiberglass laminate for maximum stiffness and durability. Left curve