NIKE Women's Air Zoom Ultra Tennis Shoes Synthetic Weight: approx. 8.8 oz. Upper: Mesh upper is lightweight and breathable. Flywire cables provide dynamic lockdown Insole: Zoom Air units in the forefoot provide responsive cushioning. Synthetic skins on the forefoot and lining the collar add durability. Midsole: TPU shank in the midfoot provides lightweight torsional stability. Phylon midsole provides lightweight cushioning.