The upper of these shoes is made of breathable engineered mesh material, which also includes partially recycled linings. The tongue and collar are lined with soft Lycra material for added comfort. The insole is cushioned with an anatomical Precise-Return technology and provides additional support for your arch and heel. These shoes are specifically designed to fit women, with a narrower heel, roomier toe area, and a softer cushioning for your feet. The midsole is made of EVA material and features RE-ZORB active foam for extra cushioning.