A lightweight Fibreglass Composite shell with Microtex & Wing Flex technology provides the ideal level of comfort for performance riding without affecting the overall stiffness of the saddle. K:ium rails are lighter than standard Cr-mo rails & help to reduce vibrations from the road without the additional cost of carbon. Spine Concept Fiziks guideline to choosing the perfect saddle, Spine Concept offers three different versions depending on varying degrees of flexibility to create a comfortable, high performance riding position. The Fizik Arione R3 K:ium is designed to fit Snakes.