Nike Women's Free TR Fit 2.0 Training Shoes. Synthetic. Rubber sole. No-Sew Construction - At upper to minimize seams for less irritation, meaning you can concentrate on your workout. Air Mesh Upper - For maximum breathability, keeping your feet cool and dry. Phylite Midsole - With engineered longitudinal and latitudinal sipes for a much better and effective running experience. Deep Flex Grooves - Located along the outsole for greater flexibility, smoother and efficient ride. Flexible Neoprene Heel Counter - Supports the foot and keeps it in place.