Spidi XP3-S Sport Boots The evolution in the 3 series, this racing boot is ideal for mid to high level sport riders. With interchangeable slider, polyurethane shields and a solid chassis this is a race ready, performing boot good also for sport touring, Evolution of the classic XP1. Efficient side protector and slider. Variably thickness Polyurethane rear fin which reduces air turbulence and increases shock absorbing factors. Polyurethane lateral ankle slider. Thermoformed carbon ankle protection. High cushioning with peculiar shape able to better fit leg morphology. Bi Component plastic toe slider.