Spenco PolySorb Proform Ultra-ThinSpenco PolySorb ProForm Insoles are ultra-thin and provide contoured, flexible support. Made for walkers, runners and joggers seeking additional comfort and cushioning without sacrificing toe room. Offers increased shock absorption and heel strike protection. Reduces friction to help prevent blisters. Adds increased energy return for improved athletic performance. SpenCore™ heel and forefoot cushioning, Lightweight PolySorb® polyurethane heel cup and contoured arch support. Low-friction top cloth with Silpure Antimicrobial helps prevent blisters while controlling odor. Unconditionally guaranteed for one full year.