Monocoque unidirectional carbon shaft, 2-bolt adjustable alloy clamp FlexLogic carbon layup provides vertical compliance with no loss of lateral or torsional stiffness 38mm rail clamping area, reversible clamp offers 5 or 15mm offset. 179g (27.2x400mm) LINKSystem clamp adapters sold separately: Vector Evo Saddles BTI #RC4199, Selle Italia Monolink BTI #RC4197