What are the PU Gel Foam Insoles? The durable PU gel foam insoles provide superb cushioning & excellent thermal insulation. Comfortable to wear the gel insoles are breathable, wick moisture away from the skin & absorb odour, making them ideal for walking, hiking & athletics. How do the PU Gel Foam Insoles work? Absorbing up to 50% shock upon impact, these durable gel foam insoles feature a massaging wave system. The grooves in the gel act like tiny springs to absorb impact on pressure points in the heel & the ball of the foot. Designed to provide additional cushioning & stability, the gel insoles ensure the arch of the foot is supported for maximum comfort. What size do I need? Men: UK 7-11 Women: UK 5-9 Can be trimmed to fit