Posture 3 – Performance: Neutral pelvic rotation for a balance of comfort and efficiency;WSD – Engineered specifically to provide a better fit and greater comfort for women;Contour Relief Zone – Recessed saddle cavity eases pressure on soft tissue;Size Specific Curvature – Curvature of each saddle is designed specific to its width;Hollow chromoly rails;Nylon composite shell;inForm BioDynamics – Products designed to optimise your natural movement for sustained, higher performance