Spenco PolySorb Men's / Women's CrossTrainer Insoles absorbs shock, re-energizes feet and reduces friction. A contoured layer of lightweight polyurethane bonds to a closed-cell nitrogen-injected Spenco material to help cradle the heel and support the arch. Added cushioning in the heel strike zone and forefoot area help protect the back and front of the foot during any activity. The polyurethane and closed-cell nitrogen-injected material insole provides heel and arch support. Reinforced forefoot cushion provides extra protection for the ball of foot. Four-way stretch nylon helps reduce friction and heat build up, helping you avoid foot and heel blisters and calluses. Awarded the Seal of Acceptance by the American Podiatric Medical Association.