Nike Women's Free 5.0 V4 NS PT Running Shoe Synthetic-And-Mesh Made in USA Rubber sole Modified innersleeve construction made of sandwich mesh provides a dynamic, sock-like fit that hugs the foot but still allows for easy on and off Minimalistic, molded sockliner mimics the curvature of the foot to provide a great fit, enhance comfort and add support Deep flex-grooves along the length and width of the midsole enhance flexibility and help maintain stability