The SpencoŽ Performance Gel Insole sets the standard in gel insoles. Dual-density Thermo Polyurethane Rubber gel combines superior cushioning and energy return where the foot needs it the most. Correct arch support provides for a better overall fit, comfort and performance. True heel cupping gives extra cushioning and stability to the heel. Slip-Resist design helps keep the insole in place while the antimicrobial top cloth helps eliminate odor causing bacteria and reduces friction. Unconditional one-year guarantee.