The Spenco Polysorb Cross Trainer Insole offers the best combination of shock absorption and energy return. Ideal for athletes or anybody looking for additional cushioning in the forefoot or heel this insole works best in athletic tennis basketball and training shoes with removeable insoles. Effective enough to use in all team sport competitions and training the Spenco Polysorb Cross Trainer offers energy return for improved athletic performance. Made with Spencore a lightweight material that absorbs shock and impact this insole provides comfort and cushioning. Polysorb polyurethane foam provides arch and heel support while a Spencore heel plug provides extra cushioning and shock absorption. An SBR forefoot cushion provides cushioning and energy return for high impact sports. The top layer is made with a 4-way stretch fabric that prevents blisters while controlling odor with Silpure antimicrobial technology. The Spenco Polysorb Cross Trainer comes with a one-year unconditional guarantee.