adidas Men's adiZero XT Running Shoe 100% Synthetic Leather 2 density asymmetrical exterl heel counter for optimal comfort, fit and stability Flexible rubber cupsole for grip and durability Perforated insole for breathability adiPRENE midsole insert for comfort and shock absorption; adiPRENE insert for forefoot propulsion and efficiency Injected EVA for long-term lightweight cushioning