All the features of our #3931300 series but with a stiffer more rigid arch support and SpenCore Forefoot Pad * Perfect for serious athleted needing stiffer more rigid support * Most rigid replacement insoles offer some motion control and stability but that?s where the similarity ends: Spenco© Total Support© Insoles feature our patented 3-POD© Modulation System: By positioning pods with varying degrees of hardness beneath key areas of the foot Total Support© Insoles change the ground forces reaching the foot during activity * This tunes the ride for increased performance and superior comfort while helping to reduce over-pronation--a common problem that causes foot leg and back pain * Spenco© Total Support© Insoles are unconditionally guaranteed for one year