inForm Posture 3 - Performance: Neutral pelvic rotation for a balance of comfort and efficiency.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.Abrasion Resistant - Durable material at vulnerable spots for increased life and looks.inForm BioDynamics - Products designed to optimise your natural movement for sustained, higher performance.