New Balance Women's WR1906 NBX Running Shoe 100% Synthetic and mesh Rubber sole N-ergy is a resilient engineered elastomer designed to provide shock absorption and responsiveness for the optimal ride ABZORB FL midsole foam provides an amazing blend of comfort and performance with DuPont Engage and isoprene rubber Stability Web provides optimal arch support thats both rigid and lightweight while preventing midfoot flex NLOCK is an integrated lacing and webbing system that provides optimal fit, support and security LockDown Liner is an adjustable, internal liner that is integrated into the lacing to provide a custom fit and securely hold the midfoot