Nike Air Zoom Vapor X Knit Women's Tennis Shoes Black/White/Hot Lava : The Nike Zoom Vapor X Knit hard court tennis shoes feature the very latest technology made for the game of tennis. This model features the reliable cushioning from the Nike Zoom Air unit, but with a modern twist. The knit upper provides lightweight, breathable support of the feet that allows for powerful, explosive movements between shots. Upper: Features a circular-knit material is breathable and lightweight. High-strength yarns provide support of the feet during movement on the court. Midsole: Soft foam midsole with Zoom Air unit in the heel offers low-profile responsive cushioning. A stretchy internal sleeve hugs the feet for a sock-like fit. Outsole: Rubber outsole with XDR compound on the heel and forefoot provides multi-surface traction and durability. A pattern of small triangles on the outsole adds durability to high wear areas.