adidas adiZero RC - Men's An incredibly lightweight racing flat for competitive runners traveling distances from 5K to the marathon. Lightweight air mesh upper for ventilation with microfiber synthetic for a soft, glove-like fit. Non-slip lining for performance and comfort. EVA insole for comfort. Full forefoot adiPRENE+ midsole propels you forward for an efficient running gait. TORSION System for midfoot integrity. adiWEAR outsole for durability in high-wear areas. Flex grooves for forefoot flexibility. Wt. 6.5 oz.