Aliante R3 K ium Aliante saddles are the widest and most longitudinally waved of fi'z k's trio of pro-cyclist-developed Spine Concept models. Aliante R3 K ium is light, flexible and agile, enabling you to perform at your best. It features a composite fiberglass co-injected Nylon shell for support with optimized stiffness to-weight construction with Twin Flex technology which combines a song, stiff carbon layer with a flexible, comfortable carbon layer and an alloy K ium rail for light weight and strength. Made for Bull. Shell Composite glass co-injected Nylon TwinFlex Rail K ium. Cover Thermowelded Black Microtex Rear Cover Anthracite/Black Microtex Shell Composite glass co-injected Nylon TwinFlex Rail K ium Scuff Guards Black Weight 220 gr Dimensions 275x152 mm Integrated Clip System compatible