Low arch signature Superfeet shape adds stability and comfort to your shoes, reducing stress on feet, ankles, knees, and back. Improves efficiency, reduces fatigue, and supports every step. Responsive EVOLyteA(R) carbon fiber cap and thin, high-density comfort foam combine to create smooth and efficient energy transfer throughout your gait, from foot strike to toe-off. Thin profile made to fit well in slim-fitting shoes. Arch HeightLow ThicknessThin CushionSemi-Firm Size Description B Junior: 2.5 - 4 /Women: 4.5 - 6 C 5.5-7 Men / 6.5-8 Women D 7.5-9 Men / 8.5-10 Women E 9.5-11 Men / 10.5-12 Women F 11.5-13 Men / 12.5-14 Women G 13.5-15 Men