Mizuno Women's Wave Unite 2 Running/Training Shoe - Black & Optic Yellow Air Mesh Upper for superior feel, breathability, and comfort. - Wave Technology provides the right amount of cushioning and stability for the athlete. Lightweight, responsive, and durable cushioning copolymer. Combination and rubber/blown rubber forefoot outsole design for cushioning, flexibility, and durability. Rubber that allows for longer wear in high impact areas and supplements traction at heel strike. Premium footbed foam enhances cushioning for superior comfort.