NIKE Women's Air Zoom Vapor X HC Tennis Shoes Synthetic Rubber sole A Zoom Air unit in the heel offers low-profile, resilient cushioning from swing to swing. The Dynamic Fit system wraps your foot from the bottom of the arch up to the laces for a glove-like fit. The full-length TPU foot frame wraps up the outside of your foot for added stability on every turn and swing. Padded collar provides additional comfort Built-up rubber on the toe increases durability and protection from drag