Flexibility Flex-H concept with flex grooves supports heel-to-toe transition. Energy restoration Exclusive Propulse Motion concept for more dynamic walking. Comfort Multi-seam neckline for unrestricted, unrestricted walking. chafing Sticky Rubber outsole with large ground contact area Stability Sole for three-hour walks three times a week without loss of cushioning Light weight Lightweight material: 310 g for size 43