Dual-layer mesh tongue with a sweat-wicking outer layer that pulls sweat away for comfort. Ultra-soft collar lining for a comfortable, snug fit. Reflective elements for visibility in low light. Waffle pistons on the outsole for added cushioning and response. Deep cuts along the length and width of the base for flexibility and a more natural, efficient stride. Extra-durable rubber in high-wear zones to enhance durability and traction without added weight. Weight: 5.1 ounces (women's size 8) Nike+ ready.