Why use Scholl Gelactiv Sport? It is developed to effectively absorb shocks and help reduce excessive pressure of running or sports. With a strong arch support and cushioning it is carefully designed to fit athletic footwear. GelActiv technology: GelActiv technology provides superior shock absorption vs not wearing insoles and cushioning performance, with the ergonomically designed gel insert integrated in the insole. GelActiv is effective in absorbing micro shocks and helps reduce the excessive pressure of activities like walking or running. Impact cushioning for joints*.*Joints refers to joints on your lower leg like knees and ankles.Directions for use: Trim to fit if necessary. Cut along the outline that matches your shoe size or use the original insole as a guide.