This insole fit for sports and protect the heel and base of the feet.Instant relief from painful with shock-absorb. Fit for flat feet,plantar fasciitis,heel pain,foot callus,foot corn,heel spur symptoms. Comfort and cushioning for all types of leisure or everyday footwear.Great for jogging,running,climbing,basketball,football,cycling,golf,tennis etc. Instruction for Use Remove the current insoles from your shoes, Place new insoles with your current insoles back to back. If your original insoles are shorter than the new insoles, you can trim along the outline on the bottom of the new insoles to match the size of your current insoles. Insert the new Insoles into your shoes (do not put both the new insoles and your current insoles in the shoes at the same time as it would be too thick and wide). (Black) High elastic Memory foam Material. (Yellow) Soft Memory foam Material. Doctors highly recommend that you replace your insoles every 3 months to promote healthy feet. Tips Keep your shoes dry. Remove the original sole of the shoe before putting the soft insole. Put the insoles in a ventilating place to keep them dry and fresh. High temperature exposure is strictly prohibited.