BONTRAGER AFFINITY RL 154MM-BLK Posture 3 - Performance: Neutral pelvic rotation for a balance of comfort and efficiency WSD - Engineered specifically to yield 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 154MM/250G