New Balance WR817MC Womens Running Shoes. Meet your everyday training goals in the New Balance WR817MC. Synthetic Mesh upper provides lightweight comfort and support. A blend of DuPont Engage Isoprene rubber and proprietary materials provides the ultimate ride. ACTEVA in midsole is superior light weight foam with exceptional durability. N Lock external support system ensures shoe is pulled snugly around your midfoot. Rollbar TPU posting system minimizes rear foot movement that, when combined with TS2 system, achieves the ultimate in motion control. Phantom Liner reduces abrasion and discomfort. N Durance in outsole is rubber compound for maximum durability in high wear areas.