NIKE Flex Run 2015 Womens Running-Shoes 709021 synthetic-and-leather Asymmetrical upper features fused mesh and foam materials for breathability Breathe Tech construction added to lateral side for improved airflow and support Synthetic leather wraps added to the medial side for a more secure fit Phylite midsole with a Phylon core is soft, durable and lightweight to improve your ride Phylon foam is pressure mapped to provide a customized fit and feel